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[Powered by Google Translate] [Wiki 9]

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[David J. Malan - Chuo Kikuu cha Harvard]

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[Hii ni CS50. - CS50.TV]

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Wote haki. Karibu tena. Hii ni CS50, na hii ni mwanzo wa wiki 9.

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Leo sisi lengo hasa juu ya kubuni, tena katika mazingira ya C

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lakini katika mazingira ya PHP na kidogo ya SQL na kidogo ya JavaScript,

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hasa kuelekea mwisho wa wote wawili pset 7 na pia mradi wako wa mwisho.

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Kwa kweli, kama wewe ni katika hatua ya kuwa katika mradi wako wa mwisho

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ambapo labda kama wa saa moja au zaidi iliyopita wewe angalau kuanza kutoa baadhi ya mawazo

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kwa mradi wako wa mwisho na unachokifikiria Ningependa kushirikiana na wanafunzi 1 au 2,

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kama wewe ni kuwa na matatizo ya kuunganisha na alisema wanafunzi,

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jisikie huru kujaza fomu katika cs50.net/partners/form.

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Ni tu anauliza wewe ni nani, ni aina gani ya mradi wewe ni kufikiri kuhusu,

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ambapo kuishi tu kwa sababu vifaa.

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Na kisha kama unataka kuweka jicho kwenye wiki ijayo au hivyo URL spreadsheet huko,

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basi unaweza kuona toleo kusoma tu ya doc Google

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ambayo sisi ni kukusanya habari.

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Hivyo kama unataka kufanya kazi na mtu, kwa njia zote jisikie huru kufikia nje kwa watu

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kupitia utaratibu huo.

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Lakini wengi wa folks kufanya kazi solo. Hiyo kabisa faini.

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Hivyo si kujisikia kwamba hii ni kwa njia yoyote lazima.

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Siku ya Ijumaa ilikuwa mimi tu na wachache wa timu katika hapa,

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tupu ukumbi kwa sehemu kubwa.

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Kuna walikuwa 3 watalii wamekaa huko, ili kwamba ilikuwa kidogo Awkward.

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Nini sisi aliyesema kuhusu alikuwa database na kuongelea pset 7 kidogo.

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Na kama hakuwa na kutokea kwa kukamata kwamba kwenye video bado tu, kwamba ni faini.

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Nitajaribu kufafanua masharti yoyote kwamba sisi vinginevyo kuchukua kwa nafasi

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msingi hotuba ya Ijumaa.

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>> Lakini leo sisi ni kwenda kujaribu kupata kwa uhakika

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ya si tu kuwa na uwezo wa kufanya kitu kama pset 7

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lakini kwa kweli kuelewa nini kinaendelea chini ya Hood,

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hasa baadhi ya matumizi ya kwamba sisi kuweka katika faili functions.php

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kufanya maisha yako kidogo rahisi lakini ili hatimaye kuelewa

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hivyo kwamba wakati magurudumu mafunzo kufika mbali katika wiki chache bado unaweza kuishi

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katika ulimwengu wa kweli na kufanya mambo haya bila mfumo CS50 chini wewe.

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Hii _SESSION $, kwa wale ambao ni ukoo

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au ambao tayari hawakupata video juu ya Ijumaa, nini KIPINDI tufanye

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katika PHP makao maombi ya mtandao?

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Hii ni variable superglobal, ambayo ina maana ni sawa katika roho kwa GET na POST

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na wengine wachache, lakini ni kitu gani hii muhimu kwa ajili ya?

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>> Nini ni KIPINDI kutumika kwa? Yeah. [Mwanafunzi] magogo in

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Samahani? [Mwanafunzi] magogo in magogo in Kweli.

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Katika pset 7 sisi ni kutumia hii superglobal KIPINDI kuwezesha magogo in

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Na nini kizuri kuhusu superglobal hii ni kwamba ni safu associative.

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safu associative, wanakumbuka, ni tu safu lakini ambao fahirisi tena kuwa idadi

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kama 012. Wanaweza kuwa idadi au wanaweza kuwa hata masharti.

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Na hivyo kama wewe ve dived katika pset 7 bado, unaweza kukumbuka kuwa sisi ni hifadhi muhimu kuitwa ID

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ndani ya safu hii associative ambao thamani ni kitu kama 123 -

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chochote kwa sasa watumiaji katika ID mtumiaji ni.

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motisha kwa ajili ya hii ni kwamba hata baada ya mtumiaji ametembelea kwenye localhost

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au tovuti yangu kwa ujumla zaidi na kisha wameweza umeingia,

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hata kama hawana bonyeza kiungo au kurudi tovuti yangu kwa dakika 5

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au hata saa moja au hata siku lakini wao kuondoka browser yao dirisha wazi,

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kupitia superglobal hii naweza kukumbuka kuwa wao ni watumiaji in

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>> Kwa maneno mengine, inaruhusu yangu ya kuhifadhi kidogo ya muda mrefu kitu chochote nataka kuhusu mtumiaji.

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Na unaweza kufikiria ni kweli kama mwili wa gari ununuzi.

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Maeneo kama Amazon wazi basi wewe kuweka mambo katika gari ununuzi,

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lakini HTTP, itifaki kwamba mamlaka ya mtandao, ni stateless

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kwa maana kwamba wakati wewe kutembelea tovuti,

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kwa sehemu kubwa huna baadhi ya mara kwa mara ya mtandao

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kati ya browser yako na server.

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Haraka kama wewe ve kupakuliwa HTML na JPEGs na GIFs na wote,

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uhusiano inakwenda mbali na wewe tu kuwa na nakala ya HTML na whatnot kutoka kwa seva.

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Lakini kama seva anataka kukumbuka kitu kuhusu wewe,

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ni mzigo kwenye server kwa kweli kurekodi kwamba habari.

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Na hivyo programu ambao wana mamlaka juu ya server

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unaweza kuweka zaidi kitu chochote unataka ndani ya safu hii superglobal associative

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na itakuwa kuna wakati mwingine mtumiaji anakuja nyuma,

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kama ni dakika au hata siku chache baadaye, isipokuwa wao karibu browser yao dirisha,

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ambapo kiwango KIPINDI kutoweka.

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Hivyo ni ephemeral kuhifadhi, ni yasiyo ya kudumu, na ni maana ya kwenda mbali

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haraka kama mtumiaji atakapokamilisha browser yao - sio tu kwamba tab, mara nyingi browser nzima,

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hivyo kwa ufanisi magogo nje ya mtumiaji.

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Hivyo jinsi ni kitu kweli hii kutekelezwa?

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Hebu tuangalie kwa haraka katika mfano rahisi sisi inaonekana katika siku ya Ijumaa.

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Kwa wale unfamiliar, ilikuwa rahisi kama hii.

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Hii ni ukurasa wa mtandao ambao lengo pekee katika maisha ni kuwaambia mimi

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mara ngapi nimetembelea ukurasa huu.

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Hii ni mara ya kwanza hapa Jumatatu kwamba mimi alitembelea yake, hivyo anasema 0 nyakati.

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>> Lakini kama mimi kuanza reloading ukurasa huu, inasema 1 wakati, 2, 3, 4, 5,

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na hii hatimaye kuweka tu juu ya kuhesabu juu, juu, juu, juu, juu

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kwa muda kila mimi kwa kweli bofya Reload juu yake.

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Hivyo jinsi ni kufanya kazi hii? Hebu kwenda ndani ya faili hili aitwaye counter.php.

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sehemu ya juu ya yote ni maoni bluu, lakini sehemu ya kuvutia ni hapa.

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On line 13 sisi wito session_start kazi,

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na kwamba ni literally wote unahitaji kufanya kama unataka kuwa na uwezo

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hii superglobal maalum iitwayo $ _SESSION.

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Kwamba inafanya wote iwezekanavyo, na tutaweza kuona katika wakati gani kwamba wote iwezekanavyo.

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Katika mstari 16 ilani nini mimi kufanya.

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Kama ufunguo, iitwayo counter - kwa maneno mengine, thamani index - "counter"

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lipo ndani ya safu hii inaitwa KIPINDI, basi je, Mimi kufanya na ni katika mstari chini?

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Nini ni mstari 18 kufanya?

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>> [Inaudible mwanafunzi majibu] Nini hiyo? [Mwanafunzi] Kuhifadhi thamani. Nzuri.

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Ni hifadhi thamani hiyo katika KIPINDI sasa hivi katika variable mpya ndani ya muda mfupi,

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$ Counter katika lowercase wote.

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Ona kwamba PHP tayari kuwa kidogo wavivu hapa.

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Notice hatuna yoyote kutaja int au kuelea au kamba au kitu kama hicho

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kwa sababu PHP ni weakly typed, ambapo huna kutaja aina ya kutofautiana,

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na katika kesi hii hapa nimepata hata alitangaza kuwa bado.

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Mimi kutangaza kuwa ndani ya braces haya curly na tofauti na C, hii ni kweli sawa.

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Hakuna jambo jinsi undani nested tamko variable ni katika PHP -

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ndani ya curly Brace, ndani ya curly brace na kama -

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itakuwa wakati huo katika wakati zipo kwa ajili ya salio wa mpango,

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kwa bora au mbaya.

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Hivyo mara moja inakuwa ya kimataifa haraka kama unaweza kufafanua kama sisi ni kufanya hapa.

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>> Vinginevyo, kama si kupata kwamba kuna kitu katika superglobal KIPINDI,

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Mimi nina inaonekana initializing hii counter variable 0,

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hivyo tu kuchukua user haijawahi hapa kabla.

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Na kisha hii bila shaka ni incrementing counter jinsi gani?

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Mimi nina uppdatering thamani hiyo ndani ya safu hii associative

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kwa kuweka ni sawa kwa kila counter sasa ni + 1.

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Kama mimi kitabu chini hapa kwa HTML ya ukurasa, ni kweli pretty rahisi.

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Mimi wote katika mwili wa ukurasa huu, "Wewe alitembelea tovuti hii ili-na-hivyo mara."

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Na hii ni kujenga PHP.

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Kama wewe kufanya <=, hii ni sawa na kile ufanisi kazi?

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Ni kweli sawa na kitu kama printf, ambayo tumeona mara nyingi katika C,

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ingawa kama unaweza kujua tayari kutoka spec katika pset 7,

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magazeti pia ni kazi ambayo tu Prints kitu nje, haina kweli matumizi ya namba format,

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na unaweza kweli kusema echo pia.

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Wao ni wote milele hivyo tofauti kidogo ingawa athari wavu ni hatimaye sawa.

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Hivyo hii ni sawa na matumizi ya ishara ni aina ya njia ya kifahari ya kufanya hivyo

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zaidi succinctly kuliko wewe ili vinginevyo kuwa na uwezo.

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Basi hiyo ni tovuti hii yote gani. Ni Prints nje thamani ya counter.

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Je, huu wote kweli yanatokea?

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Unaweza kukumbuka wiki au hivyo iliyopita sisi kuanza kuangalia chini ya Hood

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jinsi ya ukurasa wa mtandao kazi kwa kutumia tab Inspekta.

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>> Chrome ana hili wote katika toleo la Mac, toleo Windows, na hata toleo Linux,

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na Firefox na IE na taratibu sawa ambapo una hii debugger kujengwa katika

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ndani ya browser.

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Hebu tuangalie yafuatayo.

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Sisi tumepewa rundo zima la tabo hapa, na kukumbuka kuwa moja leftmost ni Elements,

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na hakuna jambo jinsi godawful HTML na javascript ni katika ukurasa,

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kukumbuka kwamba kwa tab Elements unaweza kweli navigate HTML hierarchically

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na nzuri na neatly.

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Hivyo kama wewe ni kujaribu kujifunza kutoka tovuti kama Google au Facebook

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au kweli tovuti yoyote, kutambua kwamba wewe pengine bora mbali

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kuangalia chanzo code njia hii kinyume na viewing chanzo mbichi,

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ambayo inaweza kuwa fujo, kama tumeona hasa kwenye tovuti ya Google.

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Hivyo kama mimi badala bonyeza tab Mtandao hapa,

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hebu angalia nini kinaendelea wakati mimi kutembelea ukurasa huu.

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Kwanza napenda wazi cache yangu.

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Mimi nina kwenda katika vipimo katika Chrome na kisha kwenda Historia

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na kisha Wazi data zote kuvinjari.

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Unaweza kutumika kwa kufanya hivyo kwa madhumuni mengine, [kicheko]

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lakini linapokuja tovuti zinazoendelea, ni kweli muhimu -

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kama wewe ni laughing unajua. [Kicheko]

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Ni kweli kweli muhimu wakati wa kuandaa tovuti kwa sababu ukweli ni

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mambo kama biskuti na mambo kama files cached HTML, cached JavaScript files

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unaweza kweli kuwa maumivu ya kichwa kubwa, kwa sababu kama kwa sababu yoyote

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browser anaamua cache baadhi faili na bado wewe Umefanya mabadiliko kwenye faili kwamba kwenye server

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lakini kivinjari si kweli akagundua kwamba faili imebadilika

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na kwa hiyo si kweli re-download hivyo hata wakati bonyeza kifungo Reload,

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moja ya njia surefire tu kuhakikisha kosa si kwa code yako,

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ni pamoja na tabia ya kivinjari, ni kwenda katika hapa katika browser yako

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na tu kufuta historia nzima hivyo kwamba kuna mkanganyiko hakuna.

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>> Na kisha kama kweli unataka kuwa Paranoid, kuacha browser, restart yake,

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na kisha kuhakikisha wote ni kufanya kazi kama ilivyotarajiwa.

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Hivyo katika muda mfupi, clearing cache ni nzuri wakati wa kufanya maendeleo.

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Hivyo hapa tuna tab Network.

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Mimi hapo awali alikuwa alitembelea tovuti mara 9, lakini napenda kwenda mbele sasa na bonyeza Reload.

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Na mimi nina nyuma chini ya 0.

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Hebu kweli kuona jinsi gani ni kwamba superglobal hii KIPINDI unatekelezwa.

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Mimi naenda bonyeza juu ya ombi 1 HTTP lililofanyizwa,

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na dirisha hili debugging lets mimi kuangalia ndani ya kwamba.

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Hapa naona tu majibu kutoka server, ambayo si ya kuvutia.

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Nimeona hii katika idadi yoyote ya njia.

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Lakini nini kitaalam kuvutia ni headers.

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Kama mimi kitabu chini hapa na kuzingatia ombi headers na bonyeza mtazamo chanzo,

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nini mimi kwenda kuona ni halisi ombi HTTP

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kwamba tu akaenda kutoka browser yangu kwa server,

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GET kuwa neno operative na kisha / counter.php kuwa jina la faili,

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HTTP/1.1 tu kuwa toleo la HTTP kwamba browser yangu ni kutumia.

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Hii line hapa ni ukumbusho kidogo kutoka browser kwa server nini jina la seva ni

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kwamba anataka kuzungumza.

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Na kisha wengine wa hii wakati mwingine ni ya kuvutia lakini si muhimu hivi sasa.

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>> Hii ni aina tu ya udadisi.

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Cryptic ingawa kamba hii ni, wakati wowote browser yako kutembelea tovuti

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ni taarifa server nini unatumia browser

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na nini mfumo wa uendeshaji unatumia na nini toleo yake.

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Hivyo kama wewe ve umewahi kujiuliza tovuti jinsi kama CNN na whatnot

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kujua nini asilimia ni ya watumiaji wa Mac kwenye mtandao watumiaji PC,

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IE watumiaji, watumiaji Chrome na kama, ni kwa sababu yote ya browsers wetu

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ni kuwaambia kila tovuti moja huko nje nini sisi ni.

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Haina lazima vyenye binafsi zinazotambulika,

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lakini haina kuwaambia server nini anwani yako ya IP ni nini na kivinjari na OS wewe ni kutumia.

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Hivyo hiyo ambapo habari hii ni.

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Lakini nini zaidi ya kuvutia sasa linapokuja vikao hivi ni header majibu.

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Hebu bofya mtazamo chanzo ijayo kwa majibu.

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Nini kuvutia hapa ni mambo machache.

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1, tulipata nyuma code ya hadhi ya 200.

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Sisi kamwe kuona hii code sasa kwa sababu inamaanisha yote ni sawa.

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Ina maana halisi sawa kwa kulinganisha na kitu kingine.

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Nini idadi sisi wakati mwingine kuona kwamba ni vibaya? [Mwanafunzi] 404.

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404, saizi ya hakuonekana, 403 unaweza kuwa kikwazo juu tayari,

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ambayo ni haramu, ambayo ina maana alisahau chmod kitu, uwezekano mkubwa.

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Na kuna rundo la wengine.

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>> Chini hapa, hii ni mambo kidogo.

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Mimi kwa kweli tu aliandika faili hii dakika chache zilizopita na pasting ndani gedit.

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Kwa nini ukurasa huu inaisha mwaka 1981 kabla ya hapo kweli ilikuwa Mtandao?

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Nini kinaendelea huko?

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>> [Inaudible mwanafunzi majibu] stempu muda. Lakini kwa nini?

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Ni kiasi fulani holela, lakini ni kweli muhimu.

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Nini hii ni kusema kwa browser yangu ni hii faili PHP ve tu aliomba tayari kimekwisha.

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Kwa kweli, ni muda wake wa miaka 30 iliyopita.

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Lakini ni nini kwamba kweli maana?

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Ni tu ina maana wakati mwingine mtumiaji ziara ukurasa huu,

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ama kwa reloading au kuandika URL katika bar anwani,

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kuhakikisha ya kwenda na kuchota nakala mpya wa hayo.

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Hii ni aina ya mfano wa busting cache,

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neno kijinga kwamba njia tu kujaribu tamaa browsers

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kutoka HTML kweli Caching hiyo wametumwa na seva

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hivyo kwamba huna ajali hit Reload na kisha kuona toleo moja ya faili.

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Wewe kweli unataka server kutuma nakala mpya.

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Hivyo ukweli kwamba ni 1981 tu ina maana kwamba kwamba ni nini appliance ni kuchagua

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kama tarehe holela katika kipindi.

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Lakini halisi line Juicy sasa ni hii moja.

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Hata kabla ya 50 wewe pengine vaguely familiar na biskuti.

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Kama ya hivi sasa, hasa miongoni mwa walio chini ya starehe au katika kati,

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kile ni kuki katika akili yako sasa hivi

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ingawa sisi ni juu ya kufanya uelewa wako zaidi ya kiufundi?

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Nini kuki? Yeah.

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[Mwanafunzi] Taarifa kuhusu user, kama kama wameweza imeandikwa mtumiaji yao jina au kitu.

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>> Nzuri. Ni taarifa kuhusu user, kama wameweza typed katika jina la mtumiaji zao tayari.

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Cookies ni njia ambapo servrar wanaweza kukumbuka kitu kuhusu mtumiaji.

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Na nini kuki kweli ni ni faili maandishi au baadhi mlolongo ya ka

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hiyo kupandwa na server ndani ya browser yako,

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na ndani ya faili kwamba au kati ya wale ka ni baadhi ya aina ya kitambulisho.

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Labda ni literally user name yako, lakini mara nyingi zaidi ni kitu zaidi cryptic-kuangalia

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kama hii kitu hapa - bo8dal3ct na kadhalika - kweli hii kubwa alphanumeric string

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hiyo ni kweli tu maana ya kuwa kitambulisho kipekee kwa ajili yenu.

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Au unaweza kufikiria kama aina ya stempu virtual mkono.

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Kama wewe kwenda baadhi ya klabu au Hifadhi ya pumbao, na kukumbuka kwamba ve kweli kulipwa

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na wamekwenda katika, wao kuweka nyekundu kidogo sticker ya mkono wako wa aina fulani,

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na kwamba kuwakumbusha watu katika counter kwamba ve tayari kulipwa

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na unaweza kuja na kwenda kama wewe tafadhali.

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Cookies ni kidogo sawa katika roho ya kwamba.

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mara ya kwanza mimi alitembelea tovuti hii, kama mimi tu alivyofanya baada ya clearing cache yangu,

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server mtandao, appliance katika kesi hii, kuweka muhuri juu ya mkono wangu

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ambaye jina lake ni PHPSESSID, kikao ID,

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ambao thamani ni kweli hii kwa muda mrefu alphanumeric kamba.

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>> Basi hiyo ni sasa aina ya emblazoned upande wangu hivyo kwamba wakati mwingine mimi hit Reload

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au manually kutembelea URL katika browser,

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browser yangu kwa ufafanuzi wa HTTP kwenda sasa muhuri mkono

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tena na tena na tena.

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Hivyo hata kama server haina lazima kujua mimi ni nani,

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wao angalau kujua kwamba mimi nina user hiyo au angalau, zaidi hasa, kivinjari kimoja.

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Na hivyo hii ni hatimaye jinsi superglobal KIPINDI ni kutekelezwa.

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server hana wazo wewe ni nani wakati wewe kupitia upya tovuti kwa ajili ya pili au ya tatu

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isipokuwa wewe sasa hii muhuri mkono.

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Na haraka kama wewe sasa kuwa muhuri wa mkono,

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server mtandao kimsingi huenda katika database kidogo ya yake mwenyewe

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na hundi, sawa, Nimeona muhuri mkono wa bo8dal3ct mtumiaji na kadhalika.

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Hebu kuona nini habari programu ina kuhifadhiwa

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ndani ya superglobal kuhusu mtumiaji huyu,

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na basi mimi kuhakikisha kwamba data kwamba ni tena ndani ya KIPINDI superglobal

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hivyo kwamba programu unaweza re-kupata data kwamba

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hata kama ni kuweka baadhi ya dakika au saa iliyopita.

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Hivyo katika maneno mengine, biskuti, ambayo got rap mbaya kwa baadhi ya wakati

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kwa sababu ya mashaka katika browsers na wanaweza kweli kukiuka faragha yetu na yote haya,

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wao kweli kuwa shirika kubwa kwa sababu bila wao

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ungependa kuwa daima kuingia katika kila ukurasa wa Facebook wewe kutembelea

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au kila barua pepe Gmail kusoma kama browser hakuwa na baadhi ya njia ya kukumbuka

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kwamba ve tayari kuthibitishwa.

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>> Hivyo kwa njia hii cookies waliotumwa na kurudi katika waya.

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Mwingine udadisi kuhusu cookies, hasa hapa, ni kwamba hii ni kabisa katika maandishi wazi.

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Hakuna encryption kinachoendelea hapa chochote,

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na kwa kweli mimi nina kutumia HTTP kwa sasa.

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Moja ya muda wetu katika favorites CS50, ambayo sasa ni miaka 2 iliyopita,

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alikuwa karibu wakati chombo inayoitwa Firesheep alikuja nje.

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Hii ilikuwa kipande bure ya Programu ya kwamba alikuwa yaliyotolewa na mtafiti wa usalama

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kama wito wake-up kwa ajili ya jamii ya kusema tu jinsi atrociously kutekelezwa

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fulani mitambo ya uthibitishaji kwenye mtandao walikuwa.

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Hivyo kwa baadhi ya wakati, Facebook ilikuwa karibu kabisa juu ya HTTP, hakuna HTTPS.

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Na hata kama wewe hawana wazo jinsi crypto kazi, S ni salama

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hivyo ina maana kuna angalau encryption baadhi kushiriki.

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Facebook gani kutumika encrypt majina ya utumiaji na nywila,

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lakini kwa haraka kama wewe inaonekana saa yako anawafanyia au ujumbe wako au habari yako malisho,

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yote ya kwamba alikuwa kimaandishi.

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Hivyo ilikuwa Gmail mpaka tu mwaka mmoja au 2 iliyopita.

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Wakati wowote wewe umeingia, ndiyo, walitumia encryption salama,

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lakini baada ya hapo hawakuwa. Na kwa nini wapate kuwa kuwa?

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Mbona si tu kutumia cryptography wakati wote katika kesi ya kutumia kama hii?

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Nini hiyo? Nadhani nikasikia kitu. [Mwanafunzi] Speed.

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Speed, haki? Kuna njia ya kuzunguka hili.

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Lakini kama wewe tu aina ya kufikiri juu ya mantiki, kama wewe encrypt kitu,

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una kufanya angalau kidogo zaidi ya kazi.

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Katika pset 2 wakati kutekelezwa Kaisari, au Vigenere au hata ufa,

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tu uchapishaji string ni rahisi.

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Encrypting na kisha kuchapisha string minimally inahitaji kidogo zaidi kazi.

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>>  Kwa super tovuti maarufu kama Google na Facebook,

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kama una kufanya kazi zaidi kwa kila mtumiaji kwa kila ukurasa moja ya mtandao wao kutembelea,

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kwamba tu inachukua zaidi CPU wakati.

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Na kama unahitaji zaidi CPU muda, unaweza kuhitaji servrar zaidi,

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ambayo ina maana unaweza kuhitaji fedha zaidi.

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Na hivyo kwa miaka mingi hii tu kweli alikuwa si bora mazoezi.

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Watu bila kutumia encryption SSL tu wakati walihitaji.

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Lakini aligeuka, na kama huyu kwa Firesheep alifanya super wazi,

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wakati wewe guys ambao kwa sasa juu ya Facebook hivi sasa -

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Nje ya udadisi, hebu angalia kama wewe utakuwa fess up.

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Kama uko kwenye Facebook hivi sasa katika baadhi ya tab, hata kama si foregrounded,

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ni URL yako HTTP au HTTPS?

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[Nyingi wanafunzi] S. S? [Kicheko]

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Sawa. Yoyote HTTP? 1 tu? Sawa.

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Hivyo sisi wote wanaweza hack kwamba guy Facebook akaunti hivi sasa.

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Kwa sehemu kubwa hii imekuwa akageuka juu na default, angalau katika baadhi ya tovuti.

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Na hadithi ndefu kifupi, kama mtandao wako trafiki haujasimbwa,

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si tu haina HTML kwenda na kurudi katika WiFis kimaandishi,

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hivyo mambo kama cookies kwenda na kurudi katika hewa

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bila aina yoyote ya encryption.

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00:18:18,940 --> 00:18:23,540
Hivyo kama una kidogo tu ya savvy programu au kidogo ya googling ujuzi

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kupata programu ya bure ambayo gani hii, wote una kufanya ni kukaa katika Starbucks

312
00:18:27,410 --> 00:18:30,680
au kukaa katika uwanja wa ndege ambapo kuna ujumla kimaandishi WiFi

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na kuangalia tu kwa maneno kama Set Cookie-: au PHPSESSID

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kwa sababu kama una savvy kiufundi kwa kuangalia tu WiFi

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00:18:39,300 --> 00:18:43,010
kwa wote wa bits kwamba mtiririko katika hewa kwa mfano hii,

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basi unaweza kusema kwamba PHPSESSID guy hutokea kwa kuwa bo8dal na kadhalika.

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Na kisha tena kama uko kutosha kitaalam savvy au kuwa na chombo haki,

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basi unaweza tu reconfigure browser yako mwenyewe kuanza kuwasilisha kwamba muhuri mkono

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kwa Facebook.com, na kuungana na ni kwenda tu kwa kudhani kuwa wewe ni kwamba guy

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kwa sababu wote wanajua si wewe ni nani lakini kwamba una hii kitambulisho kipekee.

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Hivyo kama wewe kuiba kwamba kitambulisho kipekee na kuwasilisha ni ya server mtandao kama yako mwenyewe,

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wao ni kwenda tu kuonyesha habari kwamba mtu kulisha

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au kwamba mtu au ujumbe anawafanyia.

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>> Na napenda Google sasa jinsi ya kuamsha HTTPS Facebook labda.

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Lakini ni kweli ni rahisi kama hayo.

326
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Na hivyo Facebook na Google na kama Gotten mzuri katika hili,

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lakini kushika jicho nje wote zaidi kwa ajili ya Nje yoyote wewe kutembelea kwamba si kutumia HTTP

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na kuwa na aina fulani ya habari nyeti juu yao,

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kama ni fedha au binafsi au kama.

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Kama siyo kutumia hii, unaweza kabisa uwezekano cookies kama hii kuwa kwa urahisi sana kuibiwa

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na kisha uzua, na kwamba ni nini hasa Firesheep alivyofanya.

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You hawakuwa kuwa programu.

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Wote alikuwa kufanya ni kuwa na uhusiano Internet, download zana hii ya bure,

334
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na nini itakuwa kufanya ni wewe ingia na basi ingekuwa kuonyesha majina ya Facebook

335
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ya kila mtu katika Sanders, katika maandamano huu, hasa karibu na wewe

336
00:20:00,170 --> 00:20:03,260
na wote mnatakiwa kufanya mara bonyeza juu ya jina yao na programu automatiska mchakato

337
00:20:03,260 --> 00:20:05,970
ya sniffing kwamba cookie, kuwasilisha kwa Facebook kama yako mwenyewe,

338
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na, voilà, umeingia in

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Hivyo hii ni mwingine mmoja wa wale "kufanya hivi" rasmi.

340
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Kama una nyumba yako mwenyewe mtandao na unataka tinker, kwa njia zote,

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lakini hii haina kutambua kuvuka mstari juu ya mazingira ya chuo kikuu.

342
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>> Lakini lengo hapa ni kweli kusisitiza si jinsi ya kufanya hili

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lakini jinsi ya kuilinda dhidi ya aina hii ya mambo.

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Na ufumbuzi trivial hapa, hata kama ni yenyewe ni kiujanja,

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ni kweli kupunguza matumizi ya maeneo yoyote ambayo si kutumia https daima.

346
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Hivyo maeneo kama Facebook na Google inazidi kuwa checkboxes

347
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ambapo unaweza kuchagua katika hii aina ya kitu,

348
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na benki kuwa na hii kwa miaka kwa sababu kama hizo.

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Hivyo tu kidogo ya sababu hofu kama tunaweza. Lakini hiyo ni yake kwa kifupi.

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Hiyo ni jinsi server anakumbuka wewe ni nani.

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Na haraka kama wao wanaweza kukumbuka wewe ni nani, wanaweza kukumbuka kitu chochote kuhusu wewe

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kwamba programu ina kuhifadhiwa ndani ya superglobal hii maalum iitwayo $ _SESSION.

353
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Na kwa pset 7 tunayatumia trivially tu kukumbuka int,

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yaani ID ya kipekee ya mtumiaji ambaye umeingia,

355
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ili tujue wao tumekuwa huko mbele.

356
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Maswali yoyote kisha juu ya vikao au cookies au kama?

357
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Firesheep haifanyi kazi kama vizuri tena,

358
00:21:15,130 --> 00:21:18,310
na una kuweka kompyuta yako katika mode maalum waigaji

359
00:21:18,310 --> 00:21:20,700
hivyo wewe ni kweli kusikiliza kwa trafiki badala yenu.

360
00:21:20,700 --> 00:21:23,940
Hivyo kama wewe sasa kushusha Firesheep, kutambua hilo si rahisi kabisa kama

361
00:21:23,940 --> 00:21:26,850
kama ni mara moja ilikuwa kudhihirisha.

362
00:21:26,850 --> 00:21:29,070
Wote haki. Na si kufanya hivyo katika Sanders. Kufanya hivyo nyumbani.

363
00:21:29,070 --> 00:21:30,890
Hifadhidata.

364
00:21:30,890 --> 00:21:33,580
Moja ya mambo ya sisi alivyofanya katika pset 7 sana kwa makusudi

365
00:21:33,580 --> 00:21:37,780
mara sisi kukupa database sampuli meza kwa watumiaji kwamba ina Vitambulisho baadhi ya mtumiaji,

366
00:21:37,780 --> 00:21:41,020
majina ya mtumiaji baadhi, na nywila baadhi encrypted humo.

367
00:21:41,020 --> 00:21:44,520
Na kama utaona, kama wewe si tayari, wewe ni kwenda kuwa na mabadiliko ya meza kidogo.

368
00:21:44,520 --> 00:21:47,710
Wewe utaenda kuwa na kuongeza baadhi ya cache kwa kila mmoja wa watumiaji katika meza ya kwamba,

369
00:21:47,710 --> 00:21:51,130
na mtaenda kuwa na kuongeza mwingine meza historia, meza portfolios,

370
00:21:51,130 --> 00:21:53,310
au labda kuiita kitu kingine.

371
00:21:53,310 --> 00:21:56,740
Lakini katika suala la kufikiria juu ya jinsi ya kufanya hili, hebu kufungua chombo hiki

372
00:21:56,740 --> 00:22:00,570
ambayo sisi kutumika juu ya Ijumaa, lakini kama unfamiliar, appliance kuja na chombo

373
00:22:00,570 --> 00:22:04,680
kuitwa phpMyAdmin ambayo ni coincidentally imeandikwa katika PHP,

374
00:22:04,680 --> 00:22:07,950
lakini kusudi lake katika maisha, baada ya mimi kuingia katika hapa kama jharvard na nyekundu,

375
00:22:07,950 --> 00:22:15,160
ni kwa kunipa njia user-kirafiki ya kuangalia na kubadilisha database yangu.

376
00:22:15,160 --> 00:22:18,040
>> Mbegu kwamba mimi nina mbio appliance inaitwa MySQL.

377
00:22:18,040 --> 00:22:23,420
Hii ni maarufu sana, na ni bure wazi chanzo database hiyo ajabu rahisi kutumia,

378
00:22:23,420 --> 00:22:25,620
hasa kwa mbele mwisho kama hii.

379
00:22:25,620 --> 00:22:29,350
Nini chombo hiki inaruhusu mimi kufanya, kwa mfano, ni poke kuzunguka meza.

380
00:22:29,350 --> 00:22:30,890
Hebu kwenda mbele na kufanya hili.

381
00:22:30,890 --> 00:22:36,580
Siku ya Ijumaa sisi aliumba meza inayoitwa wanafunzi kwamba alikuwa super rahisi.

382
00:22:36,580 --> 00:22:41,680
Ni alikuwa nguzo 3 - id, jina, na barua pepe - na mimi manually kuingizwa michache ya safu

383
00:22:41,680 --> 00:22:44,420
kama Daudi na Mike katika mfano huu hasa.

384
00:22:44,420 --> 00:22:47,290
Hebu hii kidogo zaidi, na hebu kudhani kwamba tunataka kukumbuka zaidi

385
00:22:47,290 --> 00:22:49,660
kuliko tu jina na barua pepe kuhusu mtumiaji.

386
00:22:49,660 --> 00:22:53,090
Hebu bonyeza Muundo hapa juu kwa juu.

387
00:22:53,090 --> 00:22:55,440
Na tena, pset matembezi yenu kupitia hatua zinazohitajika hapa,

388
00:22:55,440 --> 00:22:58,150
hivyo usijali kama baadhi ya hii ni kidogo haraka.

389
00:22:58,150 --> 00:22:59,690
Kisha mimi naenda bonyeza hapa.

390
00:22:59,690 --> 00:23:02,270
Mimi nina kwenda kuongeza baadhi ya idadi ya nguzo baada ya barua pepe

391
00:23:02,270 --> 00:23:04,130
sababu nataka kuongeza kitu kama nyumba.

392
00:23:04,130 --> 00:23:06,640
I forgot kurekodi nyumba mwanafunzi.

393
00:23:06,640 --> 00:23:11,400
Hebu bofya Nenda, na sasa tuna fomu hii kwamba kwa bahati mbaya ni kidogo mbalimbali kutoka kushoto kwenda kulia,

394
00:23:11,400 --> 00:23:13,710
lakini nina kwenda kuwaita jina la nyumba uwanja huu,

395
00:23:13,710 --> 00:23:16,050
na basi aina mimi sasa na kuchagua.

396
00:23:16,050 --> 00:23:18,870
Basi hebu kuwa na mazungumzo mafupi kuhusu aina mbalimbali katika MySQL

397
00:23:18,870 --> 00:23:24,590
kwa sababu wakati PHP ni weakly typed na ni aina ya ina haraka na huru na aina,

398
00:23:24,590 --> 00:23:29,430
katika database hasa ni super muhimu kwa kweli matumizi ya kuandika kwa faida yako

399
00:23:29,430 --> 00:23:33,260
kwa sababu moja ya mambo MySQL na injini nyingine database unaweza kufanya kwa ajili yenu

400
00:23:33,260 --> 00:23:37,910
ni kuhakikisha kwamba huna kuweka data bogus katika database yako.

401
00:23:37,910 --> 00:23:41,850
Hii ni aina ya kosa bure kuangalia inapatikana na wewe.

402
00:23:41,850 --> 00:23:46,250
>> Maana nyumba sisi ni wazi sitaki kuwa int, ambayo ni thamani ya 32-bit katika MySQL.

403
00:23:46,250 --> 00:23:49,810
Sisi tulikuwa kuzungumza kwa ufupi juu ya Ijumaa kuhusu varchar, ambayo inasimamia kwa urefu variable Char.

404
00:23:49,810 --> 00:23:54,720
Hii ni nini? Hii utapata bayana kwamba unataka hii kuwa kamba ya aina fulani.

405
00:23:54,720 --> 00:23:56,840
Wewe si kweli kujua mapema ni muda gani,

406
00:23:56,840 --> 00:24:00,100
hivyo tutaweza kiholela kusema jina nyumba inaweza kuwa 255 wahusika,

407
00:24:00,100 --> 00:24:04,190
lakini unaweza kwenda na 32, 64 - idadi yoyote kwa kweli.

408
00:24:04,190 --> 00:24:10,700
Lakini faida ya kutumia varchar juu ya shamba iitwayo Char ni nini?

409
00:24:10,700 --> 00:24:15,110
Tu intuitively kama mimi kitabu chini hapa, kuna taarifa Char na kuna varchar.

410
00:24:15,110 --> 00:24:19,520
Varchar ni variable urefu Char; Char ni urefu fasta Char.

411
00:24:19,520 --> 00:24:24,730
Hivyo msingi tu juu ya ufafanuzi kwamba, nini faida au hasara ya kila moja ya haya?

412
00:24:24,730 --> 00:24:30,490
Kwa maneno mengine, ambaye wasiwasi kuhusu utofautishaji huo, au kwa nini huduma?

413
00:24:31,660 --> 00:24:35,750
>> Yeah. [Mwanafunzi] varchar ina zaidi kubadilika lakini inachukua hadi zaidi ya kumbukumbu.

414
00:24:35,750 --> 00:24:40,730
Nzuri. Varchar inachukua hadi zaidi - Hebu angalia. Mimi nina uhakika kama nikasikia kwamba haki.

415
00:24:40,730 --> 00:24:42,360
Je, unaweza kusema kwamba mara zaidi?

416
00:24:42,360 --> 00:24:45,850
[Mwanafunzi] Mimi alisema varchar pengine ina zaidi kubadilika lakini inachukua juu ya kumbukumbu zaidi.

417
00:24:45,850 --> 00:24:51,170
Kuvutia. Sawa. Varchar pengine inatoa zaidi kubadilika lakini inachukua hadi zaidi ya kumbukumbu.

418
00:24:51,170 --> 00:24:53,220
Mwisho ni lazima si kweli.

419
00:24:53,220 --> 00:24:56,290
Ni inategemea mazingira, lakini hebu kuja nyuma na kwamba.

420
00:24:56,290 --> 00:25:03,230
>> [Inaudible mwanafunzi majibu] Hasa.

421
00:25:03,230 --> 00:25:06,900
Ni kweli kwamba kesi Char itakuwa kawaida kutumia zaidi ya kumbukumbu

422
00:25:06,900 --> 00:25:10,950
kwa sababu Char, kama katika C, ni kama kamba, ni safu ya wahusika.

423
00:25:10,950 --> 00:25:13,690
Hivyo kama wewe kusema shamba Char ya urefu 255,

424
00:25:13,690 --> 00:25:16,910
database ni halisi naenda kukupa wewe wahusika 255.

425
00:25:16,910 --> 00:25:22,290
Na kama nyumba kuishia kuwa Mather na 6 wahusika jumla,

426
00:25:22,290 --> 00:25:25,090
wewe ni kupoteza zaidi ya wahusika 200.

427
00:25:25,090 --> 00:25:29,640
>> Hivyo varchar ufanisi anatumia tu kama wahusika wengi kama ni muhimu

428
00:25:29,640 --> 00:25:31,590
hadi kiasi upeo.

429
00:25:31,590 --> 00:25:35,470
Lakini bei ya kulipa ni kweli utendaji, uwezekano.

430
00:25:35,470 --> 00:25:39,740
Kama wewe kujua mapema kwamba wote wa masharti yako ni kwenda kuwa 8 wahusika -

431
00:25:39,740 --> 00:25:43,090
kwa mfano, tuseme kwamba wewe kuhitaji nywila ya urefu 8 -

432
00:25:43,090 --> 00:25:47,350
suala la mafanikio ya kutumia uwanja Char juu ya tukio, ingawa si mara nyingi,

433
00:25:47,350 --> 00:25:51,100
ni bayana urefu fasta kwa kitu kama nywila

434
00:25:51,100 --> 00:25:53,300
kwa sababu sasa database unaweza kuwa hata nadhifu.

435
00:25:53,300 --> 00:25:58,160
Kama anajua kwamba kila shamba Char, kila string katika safu ni urefu sawa,

436
00:25:58,160 --> 00:26:00,780
kupata nyuma hulka ya upatikanaji random.

437
00:26:00,780 --> 00:26:05,110
Unaweza kuruka karibu kati ya nyanja mbalimbali Char katika database meza yako

438
00:26:05,110 --> 00:26:07,940
kwa sababu kufikiria database kama safu na nguzo.

439
00:26:07,940 --> 00:26:11,670
Hivyo kama kila moja ya masharti ni urefu sawa,

440
00:26:11,670 --> 00:26:17,820
unajua kwamba moja ya kwanza ni katika Byte 0, moja ya pili ni katika Byte 8

441
00:26:17,820 --> 00:26:20,240
na kisha 16 na kisha 24 na kadhalika.

442
00:26:20,240 --> 00:26:24,500
Hivyo kama masharti yote ni ya urefu sawa, unaweza kuruka karibu sana kwa ufanisi zaidi.

443
00:26:24,500 --> 00:26:26,710
Hivyo kwamba inaweza kuwa faida katika suala la utendaji,

444
00:26:26,710 --> 00:26:29,420
lakini kwa kawaida wewe hawana anasa ya kujua mapema,

445
00:26:29,420 --> 00:26:32,170
hivyo varchar ni njia ya kwenda.

446
00:26:32,170 --> 00:26:36,030
Hapa ni mwingine undani kwamba hata Facebook mbio katika hatimaye.

447
00:26:36,030 --> 00:26:39,670
Ints ni kubwa, na sisi aina ya matumizi yao na default wakati wowote tunataka idadi,

448
00:26:39,670 --> 00:26:41,750
lakini ni 32 tu bits.

449
00:26:41,750 --> 00:26:46,210
>> Na hata kama Facebook haina kabisa na watumiaji bilioni 4 sasa,

450
00:26:46,210 --> 00:26:48,680
kuna dhahiri baadhi ya watu huko nje na akaunti nyingi za

451
00:26:48,680 --> 00:26:50,960
au akaunti ambayo imefunguliwa na kisha kufungwa,

452
00:26:50,960 --> 00:26:55,130
na hivyo Facebook yenyewe Naamini miaka michache iliyopita alikuwa na kipindi cha mpito kutoka int

453
00:26:55,130 --> 00:27:00,010
kwa, kama ni aptly aitwaye, bigint, ambayo ni 64 tu bits badala yake.

454
00:27:00,010 --> 00:27:02,230
Hivyo hii pia ni uamuzi design.

455
00:27:02,230 --> 00:27:06,570
Utakuwa kushangaza bahati kama mradi wako wa mwisho anarudi startup,

456
00:27:06,570 --> 00:27:10,010
ina bilioni 4 na watumiaji 1, kutoa au kuchukua,

457
00:27:10,010 --> 00:27:13,200
katika kesi ambayo kwa kutumia ints inaweza kuwa ni kidogo shortsighted.

458
00:27:13,200 --> 00:27:16,230
Lakini katika hali halisi, wako watumiaji meza pengine ni faini kwa ints.

459
00:27:16,230 --> 00:27:19,340
Lakini kwa kitu kama pset 7, kama historia meza yako,

460
00:27:19,340 --> 00:27:23,700
unaweza kuwa na maelfu mamilioni, ya watumiaji kama wewe kufuka katika etrade.com.

461
00:27:23,700 --> 00:27:26,020
Hivyo wakati unaweza kuwa na zaidi ya watumiaji bilioni 4,

462
00:27:26,020 --> 00:27:30,070
wale watumiaji una tupate kuwa na mashirikiano zaidi ya bilioni 4 baada ya muda -

463
00:27:30,070 --> 00:27:33,200
hununua na kuuza na mambo katika historia yao.

464
00:27:33,200 --> 00:27:38,090
Hivyo kama wewe kufanya wanatarajia - tena, hizi ni nzuri kuwa na matatizo kama una data sana hii -

465
00:27:38,090 --> 00:27:40,920
kama wewe kufanya wanatarajia data mno ukubwa wa int,

466
00:27:40,920 --> 00:27:47,740
kwenda na kitu kama bigint ni mwelekeo si mara nyingi kutosha iliyopitishwa na wabunifu

467
00:27:47,740 --> 00:27:49,710
kwa sababu watu takwimu kwamba si kwenda kuwa tatizo,

468
00:27:49,710 --> 00:27:51,930
lakini ni hii rahisi kuchagua jambo kubwa kuliko hiyo.

469
00:27:51,930 --> 00:27:55,380
Decimal sisi ni kutumia katika pset 7, ambayo inabainisha usahihi fasta

470
00:27:55,380 --> 00:27:59,840
hivyo unaweza kuepuka masuala yanayohusiana na ikifungwa DOUBLES na reals na kama.

471
00:27:59,840 --> 00:28:02,440
>> Na kisha kuna baadhi ya mashamba mengine hapa. Tutaweza kukitikisa mikono yetu kwao kwa kiasi fulani.

472
00:28:02,440 --> 00:28:07,270
Lakini tarehe, wakati wote kuwa na muundo eda katika MySQL,

473
00:28:07,270 --> 00:28:10,830
na faida ya tarehe hifadhi kama tarehe na si varchars

474
00:28:10,830 --> 00:28:15,730
ina maana kwamba database unaweza kweli reformat yao katika muundo tofauti,

475
00:28:15,730 --> 00:28:18,800
kama format Marekani au Ulaya au format kama - hata hivyo unataka -

476
00:28:18,800 --> 00:28:22,700
mengi kwa ufanisi zaidi kuliko kama ingekuwa tu baadhi varchar generic.

477
00:28:22,700 --> 00:28:25,150
Na kisha kuna baadhi binary nyingine, varbinary, matone.

478
00:28:25,150 --> 00:28:28,580
Hizi ni binary kubwa vitu, na unaweza pia kuhifadhi data binary

479
00:28:28,580 --> 00:28:30,750
kama vile data kijiometri katika database.

480
00:28:30,750 --> 00:28:34,350
Lakini kwa sisi tutaweza kawaida huduma kuhusu ints na varchars na kama.

481
00:28:34,350 --> 00:28:36,230
Hebu kumaliza up mfano huu kwa nyumba.

482
00:28:36,230 --> 00:28:40,030
Nyumba nitakacho kiholela kusema itakuwa 255 chars.

483
00:28:40,030 --> 00:28:42,850
Kisha default thamani tunaweza kufanya hii.

484
00:28:42,850 --> 00:28:47,440
Tunaweza na default kuweka kila mtu katika Mather House, kwa mfano.

485
00:28:47,440 --> 00:28:49,710
Hiyo ni jinsi gani tunaweza bayana kwamba database

486
00:28:49,710 --> 00:28:52,460
inapaswa kuhakikisha kwamba mtu daima ina thamani. Lakini mimi itabidi kuondoka kwamba kuwa.

487
00:28:52,460 --> 00:28:55,270
Kwa kweli, kwa watu ambao wanaishi mbali na chuo si katika nyumba,

488
00:28:55,270 --> 00:28:59,590
labda mimi kweli wanataka bayana kwamba thamani default kwa ajili ya nyumba ni null,

489
00:28:59,590 --> 00:29:04,890
na kisha mimi haja ya kuangalia hii sanduku na kuwaambia database ni sawa kama nyumba ya mtumiaji ni null.

490
00:29:04,890 --> 00:29:07,270
>> Tena, hii ni mwingine utaratibu wa utetezi unaweza kuweka

491
00:29:07,270 --> 00:29:10,590
hivyo huna hata kuwa na kuiweka katika code yako PHP lazima.

492
00:29:10,590 --> 00:29:14,630
database itahakikisha kwamba mambo ni au si null.

493
00:29:14,630 --> 00:29:17,310
Na kisha mwisho, Sifa.

494
00:29:17,310 --> 00:29:18,920
Hakuna wa haya ni kweli husika.

495
00:29:18,920 --> 00:29:22,880
Binary, unsigned - hakuna wa wale ni muhimu kwa varchar.

496
00:29:22,880 --> 00:29:24,220
Index.

497
00:29:24,220 --> 00:29:27,320
Je, mtu yeyote kujua au kukumbuka au kuwa na nadhani kama yale index ni

498
00:29:27,320 --> 00:29:29,510
kwa kitu kama nyumba?

499
00:29:29,510 --> 00:29:35,240
Hii pia ni kweli muhimu na rahisi kubuni maamuzi.

500
00:29:35,240 --> 00:29:39,200
Kwa wale ambao bado kuiona, Ijumaa sisi aliyesema ufupi kuhusu funguo msingi.

501
00:29:39,200 --> 00:29:43,240
Katika meza database, muhimu ya msingi ni shamba au safu

502
00:29:43,240 --> 00:29:46,270
ya kipekee kubainisha mistari katika meza.

503
00:29:46,270 --> 00:29:49,150
Hivyo katika meza ya sasa tuna vitambulisho, sisi kuwa na majina na barua pepe.

504
00:29:49,150 --> 00:29:52,050
Ambayo ni ya wale mgombea bora kuwa muhimu ya msingi,

505
00:29:52,050 --> 00:29:55,810
jukumu lake ni ya kipekee kutambua safu?

506
00:29:55,810 --> 00:29:57,530
Pengine ID.

507
00:29:57,530 --> 00:29:59,930
Kihoja, tunaweza pia kutumia nini ingawa?

508
00:29:59,930 --> 00:30:02,860
Labda unaweza kutumia barua pepe kwa sababu katika nadharia ni ya kipekee

509
00:30:02,860 --> 00:30:05,380
isipokuwa watu wanashiriki akaunti za barua pepe.

510
00:30:05,380 --> 00:30:09,980
Lakini ukweli ni kwamba kama wewe ni kutumia ID numeric kama 1234,

511
00:30:09,980 --> 00:30:14,170
hiyo ni 32 tu bits, ambapo anwani ya barua pepe inaweza kuwa hii ka wengi au ka hii wengi.

512
00:30:14,170 --> 00:30:16,610
Hivyo katika suala la ufanisi kwa vitambulisho vya kipekee,

513
00:30:16,610 --> 00:30:19,270
huelekea kuwa nzuri mazoezi tu kutumia int

514
00:30:19,270 --> 00:30:23,090
hata kama una baadhi mgombea string kwamba unaweza arguably kutumia.

515
00:30:23,090 --> 00:30:26,760
>> Kwa kitu kama nyumba, hii haipaswi kuwa muhimu ya msingi

516
00:30:26,760 --> 00:30:30,770
kwa sababu basi tu 1 mtu anaweza kuishi katika Mather na 1 mtu katika Currier na kama.

517
00:30:30,770 --> 00:30:32,790
Vile vile, hii haipaswi kuwa ya kipekee.

518
00:30:32,790 --> 00:30:37,830
tofauti kati ya msingi na ya kipekee ni kwamba katika kesi ya meza yetu ya sasa,

519
00:30:37,830 --> 00:30:42,620
ID itakuwa msingi lakini email si ya msingi kwa sababu sisi tu zilizotajwa -

520
00:30:42,620 --> 00:30:44,740
utendaji - lakini ni lazima bado kuwa ya kipekee.

521
00:30:44,740 --> 00:30:47,200
Hivyo unaweza bado kutekeleza uniqueness bila kufanya madai

522
00:30:47,200 --> 00:30:49,520
kwamba ni super muhimu ya msingi shamba.

523
00:30:49,520 --> 00:30:52,610
Lakini hii ni moja kabisa kusaidia: Index.

524
00:30:52,610 --> 00:30:56,180
Kama unajua mapema kwa ajili ya mradi wako wa mwisho, kwa pset 7, au kwa ujumla,

525
00:30:56,180 --> 00:30:59,480
kwamba nyumba hii shamba ni kwenda kuwa kitu wewe tafuta juu ya mengi

526
00:30:59,480 --> 00:31:01,910
kutumia Keyword kuchagua au kitu kingine,

527
00:31:01,910 --> 00:31:05,180
basi unaweza preemptively kuwaambia database kwa kazi yake ya uchawi

528
00:31:05,180 --> 00:31:10,510
na kuhakikisha kuwa inajenga katika kumbukumbu yoyote miundo data dhana muhimu

529
00:31:10,510 --> 00:31:13,770
kuharakisha utafutaji msingi nyumba.

530
00:31:13,770 --> 00:31:17,860
Labda itakuwa matumizi meza hash, labda itakuwa matumizi orodha zilizounganishwa.

531
00:31:17,860 --> 00:31:21,260
Katika hali halisi, huelekea kutumia mti, mara nyingi muundo inayoitwa B-mti -

532
00:31:21,260 --> 00:31:24,090
si mti binary lakini B-mti - ambayo ni mti pana sana

533
00:31:24,090 --> 00:31:27,370
kwamba unaweza kuona katika darasa kama CS124, data miundo darasa.

534
00:31:27,370 --> 00:31:31,800
Lakini katika muda mfupi, huna na wasiwasi juu ya kwamba wakati wa kutumia smart database programu.

535
00:31:31,800 --> 00:31:35,890
Unaweza tu kuwaambia hayo, "Index uwanja huu ili niweze kutafuta juu yake kwa ufanisi zaidi."

536
00:31:35,890 --> 00:31:40,250
>> Kama wewe kuondoka hii mbali na wewe kujaribu kutafuta kwa kila mtu katika database ambaye anaishi katika Mather,

537
00:31:40,250 --> 00:31:42,710
itakuwa kukabidhi katika tafuta linear.

538
00:31:42,710 --> 00:31:45,360
Na kama nimepata undergrads 6000 hai wote katika nyumba fulani,

539
00:31:45,360 --> 00:31:47,900
utaenda kutafuta meza nzima kupata Matherites,

540
00:31:47,900 --> 00:31:52,190
lakini kama wewe kusema Index, hopefully itakuwa kitu karibu na tafuta logarithmic

541
00:31:52,190 --> 00:31:54,510
kupata aina wale wa wanafunzi.

542
00:31:54,510 --> 00:31:56,750
Hii ni hulka bure kurejea kwenye,

543
00:31:56,750 --> 00:31:59,530
hata kama anakuja kwa bei ya baadhi ya kiasi cha nafasi.

544
00:31:59,530 --> 00:32:02,690
Mwisho, auto-increment, uwanja huu AI,

545
00:32:02,690 --> 00:32:05,830
ambayo ina maana tu kama ni int na hutaki kutunza na increment mwenyewe

546
00:32:05,830 --> 00:32:07,570
kila wakati kuna mtumiaji mpya, kuangalia kwamba,

547
00:32:07,570 --> 00:32:11,910
na kila mtumiaji kwamba anapata kuingizwa moja kwa moja kupata ID mpya.

548
00:32:11,910 --> 00:32:15,620
Hebu bonyeza Ila, na sasa hebu kupata kosa na muundo huu.

549
00:32:15,620 --> 00:32:20,200
Kama mimi kwenda katika kuvinjari, taarifa kwamba wote Mike na nyumba yangu ni null.

550
00:32:20,200 --> 00:32:22,420
Naweza kutumia phpMyAdmin kuhariri hii manually.

551
00:32:22,420 --> 00:32:25,110
Naweza kwenda katika hapa na aina katika Mather na kisha hit Enter,

552
00:32:25,110 --> 00:32:27,740
na sasa taarifa meza ni tofauti.

553
00:32:27,740 --> 00:32:29,270
Lakini taarifa mimi naweza kufanya kitu kingine pia.

554
00:32:29,270 --> 00:32:33,530
ID ya Daudi ni 1, hivyo phpMyAdmin tena ni chombo tu utawala;

555
00:32:33,530 --> 00:32:35,970
hii si kitu watumiaji yako ni milele anaenda kuona.

556
00:32:35,970 --> 00:32:38,810
Hivyo kama mimi badala bonyeza tab SQL juu juu -

557
00:32:38,810 --> 00:32:41,450
na tena, pset 7 mapenzi kuanzisha wewe zaidi ya maswali haya -

558
00:32:41,450 --> 00:32:45,260
Naweza manually nitafanya SQL muundo swala lugha amri

559
00:32:45,260 --> 00:32:56,410
UPDATE watumiaji SET nyumba = 'Pfoho' WAPI id = 1.

560
00:32:56,410 --> 00:33:00,830
Haya maswali SQL ni, nicely kutosha, pretty someka kutoka kushoto kwenda kulia.

561
00:33:00,830 --> 00:33:04,350
Update meza watumiaji, kuweka shamba iitwayo nyumba kwa Pfoho

562
00:33:04,350 --> 00:33:06,830
ambapo ID mtumiaji ni 1.

563
00:33:06,830 --> 00:33:11,480
Au mimi naweza hata kufanya ambapo barua pepe = 'malan@harvard.edu'.

564
00:33:11,480 --> 00:33:14,860
Hiyo kwa muda mrefu kama ya kipekee kubainisha yangu, kwamba ingekuwa kazi kama vizuri.

565
00:33:14,860 --> 00:33:18,810
Lakini ID huelekea kuwa juu ya utendaji, hivyo hebu kufanya hivyo.

566
00:33:18,810 --> 00:33:22,950
Hebu bonyeza Go. Okay, lecture.users haipo. Nini kosa langu?

567
00:33:22,950 --> 00:33:26,220
Nini meza kweli kuitwa hapa?

568
00:33:26,220 --> 00:33:28,770
Ni wito wanafunzi kwa sababu tu kwamba ni nini sisi alifanya juu hapa juu kushoto.

569
00:33:28,770 --> 00:33:31,860
Ni wito wanafunzi, si watumiaji. Hivyo bonyeza Nenda sasa.

570
00:33:31,860 --> 00:33:34,330
1 mstari walioathirika. Query sekondi 0.01.

571
00:33:34,330 --> 00:33:38,010
Kama mimi bonyeza Browse sasa, sasa maisha Malan katika Pfoho.

572
00:33:38,010 --> 00:33:42,070
Basi hiyo ni mwingine ladha ya SQL, lakini pset kutembea wewe kupitia kidogo zaidi ya kwamba.

573
00:33:42,070 --> 00:33:44,710
>> Kuna uamuzi kijinga nimekuwa tayari alifanya hapa.

574
00:33:44,710 --> 00:33:47,820
Ningependa kusema kwamba design hii database ni ufanisi

575
00:33:47,820 --> 00:33:51,650
kwa sababu watu zaidi mimi kuongeza meza ya wanafunzi,

576
00:33:51,650 --> 00:33:54,730
zaidi ya sisi mimi kuanza kuongeza, zaidi ya TFS mimi kuanza kuongeza,

577
00:33:54,730 --> 00:33:58,320
sisi ni kwenda kuanza kuona nini redundancies katika meza hii?

578
00:34:00,840 --> 00:34:06,020
>> Yeah. [Mwanafunzi] Kuona kwamba ni katika wanafunzi, sisi ni kutumia sawa [inaudible]

579
00:34:06,020 --> 00:34:07,360
sawa - Haki, hasa.

580
00:34:07,360 --> 00:34:10,400
Hivyo kama watu 400 wanaishi katika Mather, kutoa au kuchukua,

581
00:34:10,400 --> 00:34:15,000
hatimaye meza hii ni ya kwenda kuwa na safu 400 kwamba kusema "Mather," "Mather,"

582
00:34:15,000 --> 00:34:16,590
"Mather," "Mather," "Mather."

583
00:34:16,590 --> 00:34:19,820
Sisi ni kupoteza yote ya ka hizi, na kuna wanandoa wa takeaways huko.

584
00:34:19,820 --> 00:34:23,080
1, kuna mambo kona kesi ambapo kama mtu pays mengi ya fedha

585
00:34:23,080 --> 00:34:25,949
na renames Mather, sasa tuna kubadili database yetu nzima ya meza.

586
00:34:25,949 --> 00:34:29,730
Hiyo si kinaenda kutokea mara nyingi, ingawa mara kwa mara nyingine huitwa Pfoho Amerika ya Nyumba miaka 15 iliyopita,

587
00:34:29,730 --> 00:34:32,310
hivyo ndivyo inavyokuwa. Lakini si kwamba kulazimisha kwamba wote.

588
00:34:32,310 --> 00:34:36,000
Zaidi ya kulazimisha kuliko kesi kona kama ile ya wanaohitaji update data kwa wingi

589
00:34:36,000 --> 00:34:41,150
kwa database ni kwa nini hifadhi Mather tena na tena na tena na tena?

590
00:34:41,150 --> 00:34:43,020
Hiyo mengi ya chars, chars 6.

591
00:34:43,020 --> 00:34:45,500
Je, si sisi kufanya hata bora zaidi ya kwamba, hasa kwa Pforzheimer?

592
00:34:45,500 --> 00:34:48,320
Hakika tunaweza kufanya vizuri zaidi kuliko wahusika kuwa wengi.

593
00:34:48,320 --> 00:34:51,790
Mbona si tu kujiunga kitambulisho kipekee kwa kila nyumba

594
00:34:51,790 --> 00:34:55,020
na kuhifadhi kwamba kwa kila mtumiaji? Basi hebu jaribu hii.

595
00:34:55,020 --> 00:35:00,610
Badala tu ya kutumia meza ya wanafunzi, uniruhusu niende kwa hotuba database wangu hapa juu kushoto.

596
00:35:00,610 --> 00:35:02,600
Ona hapa inasema Unda meza.

597
00:35:02,600 --> 00:35:04,550
Hebu kujenga meza mpya iitwayo nyumba.

598
00:35:04,550 --> 00:35:08,880
idadi ya nguzo ni kwenda kuwa 2. Kuingia.

599
00:35:08,880 --> 00:35:11,200
Sasa nina mashamba 2.

600
00:35:11,200 --> 00:35:14,600
Mimi naenda kuwaita jina hili, na ni kwenda kuwa varchar ya urefu 255,

601
00:35:14,600 --> 00:35:18,770
>> lakini hiyo ni pretty holela. Hebu kuweka hii hapa chini kwa mkataba.

602
00:35:18,770 --> 00:35:22,840
Hivyo kuweka ID hapa juu. Hebu kutoa kila nyumba kitambulisho kipekee.

603
00:35:22,840 --> 00:35:25,360
Hebu kutoa kila nyumba jina.

604
00:35:25,360 --> 00:35:30,980
Hebu bayana kwamba kitambulisho itakuwa unsigned tu na mkataba kwa kutumia tu idadi chanya.

605
00:35:30,980 --> 00:35:35,020
Hebu kwenda mbele na kutoa hii auto-increment shamba kwa sasa.

606
00:35:35,020 --> 00:35:38,160
Na nini tunahitaji kitu kingine?

607
00:35:38,160 --> 00:35:41,010
Hebu kwenda mbele na bonyeza Hifadhi.

608
00:35:41,010 --> 00:35:42,480
Sasa nina meza ya pili.

609
00:35:42,480 --> 00:35:45,860
Angalia kama kando hii ni kidogo cryptic SQL amri

610
00:35:45,860 --> 00:35:50,280
kwamba ingekuwa alikuwa na aina manually kama si kutumia chombo kiutawala kama phpMyAdmin.

611
00:35:50,280 --> 00:35:51,990
Hivyo sababu nyingine sisi kuitumia.

612
00:35:51,990 --> 00:35:55,480
Ni ajabu manufaa ya aina ya pedagogically kwa sababu unaweza bonyeza karibu

613
00:35:55,480 --> 00:36:01,050
na kufikiri jinsi mambo kazi na tu kuiga na pasting nini phpMyAdmin alivyofanya.

614
00:36:01,050 --> 00:36:04,150
Lakini meza Unda amri ni kile tu kunyongwa, na hapa ni meza yangu.

615
00:36:04,150 --> 00:36:11,370
Hebu kwenda mbele sasa na kutumia SQL ghafi kuliko oversimplify kwa kubonyeza tab Ingiza.

616
00:36:11,370 --> 00:36:15,040
Hebu kufanya Insert KATIKA nyumba,

617
00:36:15,040 --> 00:36:22,230
na mimi nina kwenda kusema jina ya nyumba ataenda kuwa na thamani ya 'Mather'.

618
00:36:22,230 --> 00:36:24,790
Hiyo ni. Syntax Hii ni kidogo zaidi cryptic.

619
00:36:24,790 --> 00:36:26,660
Hii ni jina la mashamba tunataka Insert.

620
00:36:26,660 --> 00:36:30,390
Haya ni maadili tunataka kuingiza katika mashamba hayo. Hebu bofya Go.

621
00:36:30,390 --> 00:36:34,410
1 mstari kuingizwa sekondi 0.02. Hebu bofya Vinjari sasa.

622
00:36:34,410 --> 00:36:42,020
>> Taarifa kama mimi bonyeza Browse, kuna Mather, ambaye ni ID na automatisering namba 1.

623
00:36:42,020 --> 00:36:45,000
Hebu kufanya mwingine mmoja. Hebu kwenda katika tab SQL.

624
00:36:45,000 --> 00:36:52,950
Insert KATIKA nyumba. jina la nyumba ataenda kuwa na thamani ya Pfoho na kadhalika.

625
00:36:52,950 --> 00:36:56,350
Go. Na siwezi kuendelea kufanya hii tena na tena na tena.

626
00:36:56,350 --> 00:36:59,470
Au kama wewe kupata kuchoka kwa kutumia phpMyAdmin, unaweza kutumia tu tab Insert

627
00:36:59,470 --> 00:37:01,000
na si kuwa na aina SQL ghafi.

628
00:37:01,000 --> 00:37:04,690
Unaweza tu bang ni nje kwa haraka zaidi kwa kuandika, kwa mfano, Currier, Ingieni,

629
00:37:04,690 --> 00:37:07,610
na sasa kama sisi bonyeza Browse, kuna Currier na ID ya 3.

630
00:37:07,610 --> 00:37:09,920
Hivyo hii ni nini maana sisi na increment auto-.

631
00:37:09,920 --> 00:37:12,280
Lakini sasa inabidi kurekebisha kitu katika wanafunzi.

632
00:37:12,280 --> 00:37:16,240
Katika wanafunzi kile lazima data aina ya shamba nyumba sasa kuwa?

633
00:37:16,240 --> 00:37:19,450
Ni lazima kuwa int, haki?

634
00:37:19,450 --> 00:37:23,950
Hivyo Lengo hapa ni sababu nje, inayojulikana kama normalize, meza

635
00:37:23,950 --> 00:37:27,940
hivyo kwamba hatuwezi kuhifadhi habari redundantly yoyote ya meza yangu.

636
00:37:27,940 --> 00:37:31,130
Na tena, njia tulipokuwa kwenye hapa itasema Mather, Mather,

637
00:37:31,130 --> 00:37:34,220
Mather, Mather, Pfoho, Pfoho, Pfoho, Pfoho, ambayo ni sana redundant

638
00:37:34,220 --> 00:37:36,240
katika suala la israfu ya chars.

639
00:37:36,240 --> 00:37:40,820
Hivyo basi mimi kwenda mbele na kubadilisha hii kwa kubonyeza Muundo,

640
00:37:40,820 --> 00:37:44,620
na napenda kwenda mbele na kuangalia mbali shamba nyumba, bonyeza lugha,

641
00:37:44,620 --> 00:37:46,990
na sasa mimi naenda kubadili hili kuwa int.

642
00:37:46,990 --> 00:37:49,490
255 ni tena husika.

643
00:37:49,490 --> 00:37:54,010
Hebu kwenda mbele na kusema kwamba faini kama ni bado null. Ila.

644
00:37:54,010 --> 00:37:55,870
Sasa wanafunzi meza imebadilishwa kwa mafanikio,

645
00:37:55,870 --> 00:37:59,090
na ilani tena nyumba ni int.

646
00:37:59,090 --> 00:38:02,220
Kama kando, kupuuza idadi katika mabano linapokuja ints.

647
00:38:02,220 --> 00:38:03,770
>> Hii ni kwa sababu ya urithi.

648
00:38:03,770 --> 00:38:06,920
Nyuma kwa siku wakati hawakuwa na GUIs, wewe badala yake alikuwa mstari amri mazingira,

649
00:38:06,920 --> 00:38:11,580
10 na 11 kwa mtiririko huo maalum ngapi wahusika unapaswa kuonyesha

650
00:38:11,580 --> 00:38:13,950
katika dirisha terminal kwa kweli kuonyesha mashamba.

651
00:38:13,950 --> 00:38:19,150
Ina chochote cha kufanya na urefu kidogo ya shamba halisi, hivyo tutaweza tu kupuuza kwamba kwa sasa.

652
00:38:19,150 --> 00:38:20,990
Sasa mimi kwenda katika meza hii.

653
00:38:20,990 --> 00:38:24,610
Na kama Daudi anaishi katika Mather, nyumba isiwe 0,

654
00:38:24,610 --> 00:38:27,350
ambayo ni int default thamani karibu null.

655
00:38:27,350 --> 00:38:29,810
Anapaswa kuishi katika nyumba 1.

656
00:38:29,810 --> 00:38:36,870
Hebu kiholela kusema kwamba Mike maisha katika Pfoho, hivyo nyumba namba 2.

657
00:38:36,870 --> 00:38:40,160
Sasa meza yangu inaonekana kidogo zaidi cryptic.

658
00:38:40,160 --> 00:38:41,960
Lakini fikiria ufanisi.

659
00:38:41,960 --> 00:38:44,860
Mimi sasa kutumia bits 32 tu kwa kutambua nyumba,

660
00:38:44,860 --> 00:38:49,530
ambayo ina maana kuna tu 1 kisheria ufafanuzi wa nyumba yangu Mather na Pfoho

661
00:38:49,530 --> 00:38:52,090
na kwamba katika meza ya nyumba.

662
00:38:52,090 --> 00:38:55,880
Hivyo kama nataka sasa rejoin mbao hizo, kufikiria njia hii.

663
00:38:55,880 --> 00:39:01,980
Hapa nina wanafunzi wangu meza, na upande wa kulia kuna idadi hii, 1 na 2.

664
00:39:01,980 --> 00:39:04,180
1 ni Mather, 2 ni Pfoho.

665
00:39:04,180 --> 00:39:08,580
Tuna idadi wale sawa katika meza hii nyingine, ambayo inaitwa nyumba,

666
00:39:08,580 --> 00:39:11,020
1 na 2 na 3 kwa nyumba hizo 3.

667
00:39:11,020 --> 00:39:14,990
Nini sisi sasa wanataka kufanya ni kuwa na uwezo katika kanuni, PHP na SQL,

668
00:39:14,990 --> 00:39:18,800
kwa aina ya kujiunga tena mbao hizo, ambapo kama hawa ni wanafunzi na hizi ni nyumba,

669
00:39:18,800 --> 00:39:22,050
tunataka namna fulani kuchanganya yao ili 1 yanaendana na 1,

670
00:39:22,050 --> 00:39:25,670
2 yanaendana na 2, na ili tuweze kufikiri ambapo Daudi

671
00:39:25,670 --> 00:39:28,000
na ambapo Mike na ambapo kila mtu mwingine anaishi.

672
00:39:28,000 --> 00:39:31,850
Ili kufanya hivi tunaweza kutekeleza swala SQL kama zifuatazo.

673
00:39:31,850 --> 00:39:40,470
CHAGUA * KUTOKA wanafunzi JOIN nyumba ILIYO -

674
00:39:40,470 --> 00:39:43,000
Na sasa mashamba nini tunataka kujiunga juu?

675
00:39:43,000 --> 00:39:49,520
Hivyo students.house = houses.id.

676
00:39:49,520 --> 00:39:54,150
>> cryptic kidogo, lakini sehemu hii ina maana halisi kujenga mpya ya muda meza

677
00:39:54,150 --> 00:39:56,690
hiyo ni matokeo ya kujiunga na wanafunzi na nyumba.

678
00:39:56,690 --> 00:40:00,340
Na jinsi gani unataka kuchanganya tips ya vidole yangu hapa?

679
00:40:00,340 --> 00:40:05,280
Kuweka wanafunzi 'nyumba uwanja sawa kwa nyumba' ID shamba.

680
00:40:05,280 --> 00:40:10,220
Na kama mimi sasa bofya Nenda, mimi kupata nyuma hasa kile walitarajia.

681
00:40:10,220 --> 00:40:15,890
Daudi ni katika Mather, Mike ni katika Pfoho, na mimi pia kuona vitambulisho vya kipekee.

682
00:40:15,890 --> 00:40:18,640
Lakini uhakika ni sasa nina meza kamili.

683
00:40:18,640 --> 00:40:23,020
Na hivyo takeaway hapa kwa pset 7 au kweli kwa ajili ya mradi wa mwisho:

684
00:40:23,020 --> 00:40:25,830
Kama wewe kujua kwamba wewe ni hifadhi yoyote kipande cha habari redundantly,

685
00:40:25,830 --> 00:40:28,850
kama ni nyumba, labda ni mji, jimbo, na ZIP

686
00:40:28,850 --> 00:40:32,050
ambapo ZIP unaweza kawaida lakini si daima kutumika kama kitambulisho kipekee,

687
00:40:32,050 --> 00:40:35,810
kufanya kwenda njia ya mazoezi ya kiakili na kisha na kitu kama phpMyAdmin

688
00:40:35,810 --> 00:40:40,660
ya factoring nje data kwamba kawaida kwa sababu hasa kama tovuti yako anapata zaidi pamoja na kutumika

689
00:40:40,660 --> 00:40:45,440
na maarufu zaidi, hii ni jinsi gani kuhakikisha kwamba kila kitu ni super haraka,

690
00:40:45,440 --> 00:40:51,930
kwa kutoa database kama mwanga wengi kama kwa uniqueness iwezekanavyo.

691
00:40:51,930 --> 00:40:53,860
Hiyo ilikuwa mengi.

692
00:40:53,860 --> 00:40:59,010
Maswali yoyote? Wote haki. Hebu kuchukua mapumziko 5-dakika huko na kujikusanya.

693
00:41:01,600 --> 00:41:03,540
Wote haki.

694
00:41:03,540 --> 00:41:08,680
Ufuatao ni mfano kwamba ilitumika baadhi ya miaka iliyopita wakati mimi alichukua CS161,

695
00:41:08,680 --> 00:41:10,960
ambayo ni ya uendeshaji wa mifumo ya darasa katika chuo

696
00:41:10,960 --> 00:41:15,160
ambayo inajulikana kwa kuwa ajabu lakini kiasi mambo ya kazi,

697
00:41:15,160 --> 00:41:19,810
na inalenga kweli juu ya baadhi ya matatizo ngazi ya chini kwamba kina katika mifumo ya uendeshaji

698
00:41:19,810 --> 00:41:22,700
na pia hata katika ulimwengu wa database.

699
00:41:22,700 --> 00:41:27,040
>> hadithi kwamba aliambiwa na profesa wangu, Margo Seltzer, kwamba mwaka ilikuwa kama ifuatavyo.

700
00:41:27,040 --> 00:41:30,990
Tuseme kwamba una kidogo Dorm friji kwa ajili yenu na roommate yako

701
00:41:30,990 --> 00:41:34,030
na wote wawili kwa kweli kama maziwa.

702
00:41:34,030 --> 00:41:36,360
Hivyo wewe kuja nyumbani kutoka darasa ya siku moja, roommate yako ni bado kuna,

703
00:41:36,360 --> 00:41:39,650
wewe kufungua friji, na wewe kutambua, "Oh damn, tuko nje ya maziwa."

704
00:41:39,650 --> 00:41:42,070
Hivyo wewe karibu fridge, wewe kutembea katika barabara kwa CVS

705
00:41:42,070 --> 00:41:45,830
na kupata katika mistari inazidi muda mrefu ya kununua baadhi ya maziwa katika CVS.

706
00:41:45,830 --> 00:41:48,470
Wakati huo huo, roommate yako amerudi nyumbani kutoka kwake au darasa lake,

707
00:41:48,470 --> 00:41:51,690
anakuja katika chumba, anafungua friji kweli kutaka baadhi maziwa,

708
00:41:51,690 --> 00:41:54,130
kuufungua friji na, "Damn, hakuna maziwa."

709
00:41:54,130 --> 00:41:57,890
Hivyo yeye au yeye anafunga fridge, anatembea nje ya mlango, na huenda kwa ABP

710
00:41:57,890 --> 00:42:00,910
au mahali fulani nyingine kuliko CVS ambapo wewe si kwenda mapema ndani ya kila mmoja

711
00:42:00,910 --> 00:42:02,790
kwenda kupata baadhi ya maziwa.

712
00:42:02,790 --> 00:42:04,820
Bila shaka dakika chache baadaye, wote wewe kupata kurudi nyumbani

713
00:42:04,820 --> 00:42:07,740
na sasa una mara mbili kama vile maziwa kama wewe kweli walitaka.

714
00:42:07,740 --> 00:42:10,670
Na kuwa maziwa, sasa ni kwenda kwenda mbaya kwa sababu wewe kama maziwa

715
00:42:10,670 --> 00:42:14,200
lakini wewe si kweli kama maziwa, hivyo sasa una sana maziwa, hivyo ni kwenda sour.

716
00:42:14,200 --> 00:42:16,830
Hii ni kubwa, kubwa hali.

717
00:42:16,830 --> 00:42:22,920
Je, inaweza kuwa na kutatuliwa tatizo hili kama ungekuwa kwanza roommate nyumbani? Ndiyo.

718
00:42:22,920 --> 00:42:25,970
[Mwanafunzi] Unapaswa wameondoka note. [Kicheko]

719
00:42:25,970 --> 00:42:28,090
Nzuri. Unapaswa wameondoka note.

720
00:42:28,090 --> 00:42:32,320
Unapaswa kuwa na kuweka note Post-au kama akisema, "Gone kwa maziwa,"

721
00:42:32,320 --> 00:42:36,830
na kisha roommate yako conceptually ingekuwa imefungwa nje ya kweli ya kufanya hivyo.

722
00:42:36,830 --> 00:42:38,010
Au unaweza kwenda 1 hatua zaidi.

723
00:42:38,010 --> 00:42:41,060
Unaweza literally lock jokofu na baadhi ya aina ya kufuli,

724
00:42:41,060 --> 00:42:44,870
na sasa roommate yako mapenzi halisi kuwa imefungwa nje ya friji.

725
00:42:44,870 --> 00:42:48,520
Kama sisi generalize nyuma ya programu,

726
00:42:48,520 --> 00:42:51,610
unaweza karibu kufikiri ya friji kama baadhi ya aina ya kutofautiana au struct,

727
00:42:51,610 --> 00:42:53,500
aina fulani ya chombo kwa taarifa.

728
00:42:53,500 --> 00:42:58,290
tatizo la msingi hapa ni kwamba wote wewe waliruhusiwa kukagua

729
00:42:58,290 --> 00:43:02,370
au kusoma hali ya muundo huu data,

730
00:43:02,370 --> 00:43:08,050
lakini wewe ni kutazamwa kwa nyakati tofauti na bado wote wewe alifanya uamuzi

731
00:43:08,050 --> 00:43:11,920
msingi juu ya hali ya dunia katika muda mfupi wale tofauti kwa wakati.

732
00:43:11,920 --> 00:43:15,570
Hivyo alikuwa na wewe umefungwa jokofu, wewe ingekuwa angalau kuepukwa roommate yako

733
00:43:15,570 --> 00:43:19,070
kutoka kuwa imekuwa na uwezo wa kukagua hali ya dunia,

734
00:43:19,070 --> 00:43:22,530
hivyo yeye au yeye hakuweza kuwa alifanya kwamba uamuzi huo.

735
00:43:22,530 --> 00:43:25,780
Hivyo database, kama ni zamu nje, kuwa na tatizo hili mara kwa mara.

736
00:43:25,780 --> 00:43:31,050
>> Hebu tuone kama tunaweza kujenga mazingira.

737
00:43:31,050 --> 00:43:34,310
Tuseme kwamba wewe ni aina ya mtu mbaya na kwenda Benki Kuu ya Marekani

738
00:43:34,310 --> 00:43:37,950
au moja ya maeneo mengine katika mraba kwamba kuwa wanandoa ATM kwa upande upande,

739
00:43:37,950 --> 00:43:41,200
na kwa namna fulani wewe figured nje ya jinsi duplicate kadi za ATM - si wote ngumu.

740
00:43:41,200 --> 00:43:42,730
Ni tu strip sumaku.

741
00:43:42,730 --> 00:43:45,180
Na hivyo nini unataka kujaribu kufanya ni kucheza mchezo huu

742
00:43:45,180 --> 00:43:49,060
ambapo wewe kuweka 1 kadi katika mashine 1, mwingine kadi katika mashine nyingine,

743
00:43:49,060 --> 00:43:51,980
na wewe kimsingi wanataka kujaribu kuchukua fedha wakati huo huo,

744
00:43:51,980 --> 00:43:54,930
kwa sababu kufikiria hadithi kwamba huenda kama ifuatavyo.

745
00:43:54,930 --> 00:43:57,350
mashine ya kushoto inachukua kadi yako na PIN yako,

746
00:43:57,350 --> 00:44:00,240
na kisha wewe sema, "Nipe $ 100."

747
00:44:00,240 --> 00:44:04,790
ATM ni programmed kwa kwanza kufanya juu ya kuchagua database yake au sawa -

748
00:44:04,790 --> 00:44:10,780
chochote database ni kutumia - kuona haina mtumiaji huyu angalau $ 100 katika akaunti yake au yake?

749
00:44:10,780 --> 00:44:16,180
Ikiwa hivyo, basi mate nje $ 100 na $ 100 kutoka Ondoa mizani zao.

750
00:44:16,180 --> 00:44:20,470
Lakini bila shaka kama kuna nyingi mashine hapa au njia nyingi za ukaguzi

751
00:44:20,470 --> 00:44:23,560
hali ya ulimwengu kuwa, kuba benki, ili kuona kiasi cha fedha una,

752
00:44:23,560 --> 00:44:26,780
kudhani kwamba tu kwa bahati mashine upande wa kushoto na kulia

753
00:44:26,780 --> 00:44:30,140
wote kuuliza swali wakati takribani sawa na kwa wakati.

754
00:44:30,140 --> 00:44:34,160
>> Na hakika hii inaweza kutokea. ATM ni kompyuta siku hizi.

755
00:44:34,160 --> 00:44:37,670
Hivyo kama mashine kushoto anasema, "Ndiyo, una angalau $ 100,"

756
00:44:37,670 --> 00:44:42,150
wakati huo huo mashine kulia anasema, "Ndiyo, una angalau $ 100,"

757
00:44:42,150 --> 00:44:47,420
kisha wote wawili kuendelea na mipango yao ya kumaliza na kweli mate nje $ 100

758
00:44:47,420 --> 00:44:50,820
na kusema, "Hapo awali alikuwa na $ 200."

759
00:44:50,820 --> 00:44:54,890
"Hebu update variable kwa sasa kuwa $ 100 kushoto katika akaunti."

760
00:44:54,890 --> 00:44:58,780
Lakini kama wote wawili kuwa checked masalio ya akaunti yako na kukuta kwamba ni $ 200

761
00:44:58,780 --> 00:45:02,000
na wote wawili kisha kufanya math na kusema 200-100,

762
00:45:02,000 --> 00:45:06,990
mashine na uwezekano ametema mbili bili $ 100 katika kila mashine,

763
00:45:06,990 --> 00:45:11,360
lakini wameweza tu updated Jumla akaunti yako ya usawa kuwa $ 100.

764
00:45:11,360 --> 00:45:15,130
Kwa maneno mengine, umechukua nje $ 200, lakini kwa sababu wao kukaguliwa hali ya dunia

765
00:45:15,130 --> 00:45:18,840
wakati huo huo na kisha alifanya uamuzi wa msingi juu ya thamani ya kwamba,

766
00:45:18,840 --> 00:45:21,930
wapate kufanya math hatimaye kwa usahihi.

767
00:45:21,930 --> 00:45:25,520
Hivyo katika hali ya benki pia kweli unataka kuwa na aina fulani ya lockout

768
00:45:25,520 --> 00:45:28,450
hivyo kwamba haraka kama wewe ve checked hali ya kutofautiana baadhi

769
00:45:28,450 --> 00:45:31,220
kwamba kweli ni muhimu, kama akaunti mizani yako,

770
00:45:31,220 --> 00:45:36,070
usiruhusu mtu mwingine kufanya maamuzi kwa kuzingatia kwamba mpaka wewe ni kufanyika kufanya kitu yako,

771
00:45:36,070 --> 00:45:38,920
ambapo katika kesi hii ni ATM upande wa kushoto.

772
00:45:38,920 --> 00:45:41,160
Funga kila mtu mwingine nje.

773
00:45:41,160 --> 00:45:44,650
Unaweza kweli kufikia athari katika michache ya njia tofauti.

774
00:45:44,650 --> 00:45:48,660
>> njia rahisi katika MySQL ni mstari wa SQL kwamba tuliyowapeni

775
00:45:48,660 --> 00:45:52,030
katika kuweka vipimo tatizo kwamba inaonekana hasa kama hii.

776
00:45:52,030 --> 00:45:57,420
Ingiza katika meza - chochote ni kuitwa - id, alama, na kushiriki, idadi ya hisa,

777
00:45:57,420 --> 00:45:59,660
maadili yafuatayo, kwa mfano.

778
00:45:59,660 --> 00:46:03,370
Kama si kusoma spec bado, huu ni mfano kuwashirikisha jinsi gani unaweza kwenda kuhusu

779
00:46:03,370 --> 00:46:07,340
kununua hisa 10 ya hisa hii senti kwa Rais Skroob,

780
00:46:07,340 --> 00:46:10,340
user ID ambao hutokea kwa kuwa namba 7?

781
00:46:10,340 --> 00:46:14,070
Hii inasema Insert KATIKA meza id zifuatazo, alama, na idadi ya hisa

782
00:46:14,070 --> 00:46:18,200
ya 7, 'DVN.V', na 10.

783
00:46:18,200 --> 00:46:21,510
Lakini - lakini, lakini, lakini - mstari wa pili ni moja muhimu.

784
00:46:21,510 --> 00:46:26,310
ILIYO duplicate KEY UPDATE hisa = hisa + MAADILI (hisa).

785
00:46:26,310 --> 00:46:28,350
Hivyo kabisa cryptic-kuangalia katika mtazamo wa kwanza.

786
00:46:28,350 --> 00:46:31,990
Lakini ukweli kwamba hoja hii SQL, hata ingawa Wraps kwenye mistari 2,

787
00:46:31,990 --> 00:46:35,920
ni 1 kwa muda mrefu swala, ina maana ni atomic

788
00:46:35,920 --> 00:46:41,000
kwa maana kwamba swala hili ama kuuawa wote kwa pamoja au si wakati wote.

789
00:46:41,000 --> 00:46:45,100
Na kwa ufafanuzi wa MySQL, kwamba ni jinsi gani wao kutekelezwa hoja hii.

790
00:46:45,100 --> 00:46:51,010
Ni kwa ufafanuzi katika mwongozo uhakika wa kutekeleza yote kwa mara moja au si wakati wote.

791
00:46:51,010 --> 00:46:54,020
motisha kwa ajili ya hii ni kama ifuatavyo.

792
00:46:54,020 --> 00:46:58,540
Kama katika kesi hii ni kujaribu kununua hisa 10 ya hisa,

793
00:46:58,540 --> 00:47:02,260
ni aina ya hadithi ileile kama maziwa, ni aina ya hadithi ileile kama ATM.

794
00:47:02,260 --> 00:47:04,970
>> Kama kufanya makosa ya si kutumia syntax

795
00:47:04,970 --> 00:47:09,610
lakini badala ya kuchagua kutoka orodha ya kuona hisa ngapi ya hisa hii senti

796
00:47:09,610 --> 00:47:13,750
haina Rais Skroob kuwa, na kudhani yeye ana hisa 10,

797
00:47:13,750 --> 00:47:19,330
na kisha baadhi kupasuliwa pili baadaye wewe kisha kufanya kauli UPDATE,

798
00:47:19,330 --> 00:47:24,810
ambayo ni mwingine taarifa katika SQL kwamba anasema kwenda mbele na kuongeza hisa 10 zaidi

799
00:47:24,810 --> 00:47:28,700
kwa 10 yake ya sasa ili walau jumla ni 20,

800
00:47:28,700 --> 00:47:33,490
Tatizo ni kwa sababu katika mifumo ya leo kwa sababu database na katika kompyuta ya leo

801
00:47:33,490 --> 00:47:35,990
una wasindikaji nyingi, nyingi cores -

802
00:47:35,990 --> 00:47:38,920
kwa maneno mengine, kompyuta unaweza literally kufanya mambo nyingi kwa mara moja -

803
00:47:38,920 --> 00:47:44,270
kuna dhamana hakuna kwamba SELECT yako na UPDATE yako katika kesi hii

804
00:47:44,270 --> 00:47:46,150
yanaenda kutokea nyuma kwa nyuma.

805
00:47:46,150 --> 00:47:49,140
Hivyo scenario mbaya itakuwa kufanya SELECT

806
00:47:49,140 --> 00:47:51,670
kuona hisa ngapi ya hii hisa senti haina Skroob kuwa,

807
00:47:51,670 --> 00:47:54,710
na kisha tu kwa bahati swala mwingine database ni kunyongwa -

808
00:47:54,710 --> 00:47:57,740
labda Skroob yake katika dirisha lingine browser kujaribu kununua hisa 10

809
00:47:57,740 --> 00:48:00,700
katika dirisha lingine kabisa, kiasi kama ATM -

810
00:48:00,700 --> 00:48:05,410
na kudhani kwamba swala mwingine anapata katika kati ya SELECT na UPDATE.

811
00:48:05,410 --> 00:48:10,210
Ni inaweza kuwa kesi hiyo Skroob sasa hupoteza baadhi idadi ya hisa

812
00:48:10,210 --> 00:48:14,340
kwa sababu mchakato mwingine ni ukaguzi hali ya ulimwengu wake,

813
00:48:14,340 --> 00:48:17,800
au yeye anapata hisa zaidi ya anapaswa kuwa.

814
00:48:17,800 --> 00:48:23,250
Sisi si kwenda katika maelezo ya nini hasa wale fulani hadithi mistari itakuwa,

815
00:48:23,250 --> 00:48:28,380
lakini uhakika ni kama wewe na kuangalia thamani ya vigezo na kisha kufanya uamuzi,

816
00:48:28,380 --> 00:48:32,500
kama kuna hatari ya mtu mwingine kufanya kitu katika kati ya wale kauli 2,

817
00:48:32,500 --> 00:48:36,220
kama inaweza kutokea katika mifumo multiprocessor, katika mifumo multicore,

818
00:48:36,220 --> 00:48:41,220
kompyuta na uwezo wa kufanya mambo nyingi kwa mara moja, mambo mabaya yanaweza kutokea

819
00:48:41,220 --> 00:48:44,530
akaunti ya benki kama kuwa debited kimakosa, kununua mara mbili kama vile maziwa,

820
00:48:44,530 --> 00:48:46,730
au katika kesi hii idadi ya makosa ya hisa.

821
00:48:46,730 --> 00:48:48,370
Lakini kuna njia rahisi kufikiri juu ya hili.

822
00:48:48,370 --> 00:48:53,290
>> Ni zinageuka kuwa SQL pia inasaidia, kama wewe configure meza yako kwa usahihi,

823
00:48:53,290 --> 00:48:56,920
kitu kinachoitwa mashirikiano, ambayo Ningependa kusema ni kweli hata rahisi kuelewa

824
00:48:56,920 --> 00:49:00,650
kuliko huu, lakini siyo 1-mjengo, hivyo ni kweli kidogo zaidi kushiriki.

825
00:49:00,650 --> 00:49:04,960
Kuna literally taarifa katika SQL kuitwa START manunuzi.

826
00:49:04,960 --> 00:49:08,300
Tu kama kuna CHAGUA, UPDATE, Insert, FUTA, na JOIN na rundo la wengine,

827
00:49:08,300 --> 00:49:10,970
kuna maneno kama manunuzi START.

828
00:49:10,970 --> 00:49:13,560
Na nini basi kufanya katika muktadha wa pset 7 -

829
00:49:13,560 --> 00:49:17,270
huna kufanya hili kwa pset 7; ni wazi alikana kama si muhimu,

830
00:49:17,270 --> 00:49:18,830
lakini kwa ajili ya miradi ya mwisho inaweza kuwa na manufaa -

831
00:49:18,830 --> 00:49:22,820
kama simu swala ya manunuzi START na kisha mwingine swala

832
00:49:22,820 --> 00:49:25,620
na kisha mwingine swala na kisha mwingine, mwingine, na mwingine,

833
00:49:25,620 --> 00:49:31,860
maswali hayo si kweli kuwa kunyongwa mpaka wewe piga taarifa SQL kutenda,

834
00:49:31,860 --> 00:49:37,220
ambapo kiwango, kama ni 2 kauli au matamshi 20, wao wote ni lazima ifanyike kwa mara moja,

835
00:49:37,220 --> 00:49:42,770
ambayo ina maana hakuna mtu mwingine anaweza ajali kununua sana maziwa au debit sana fedha

836
00:49:42,770 --> 00:49:46,340
au kununua hisa nyingi sana kwa sababu wote wa maswali yako nitafanya

837
00:49:46,340 --> 00:49:48,410
nyuma kwa nyuma kwa nyuma kwa nyuma.

838
00:49:48,410 --> 00:49:51,580
Na hii ni super muhimu, hasa wakati wewe ni kufanya kitu kama hiki.

839
00:49:51,580 --> 00:49:54,900
Huu ni mfano holela kwamba anasema hebu update akaunti ya benki

840
00:49:54,900 --> 00:50:00,200
kwa kuweka uwiano sawa na usawa - $ 1000 ambapo idadi ya akaunti ni 2.

841
00:50:00,200 --> 00:50:04,260
Na kisha kauli ya pili sasa hebu amana kwamba $ 1000

842
00:50:04,260 --> 00:50:07,310
ndani ya mtu mwingine ya akaunti ya benki ambaye akaunti namba ni 1.

843
00:50:07,310 --> 00:50:10,400
>> Kwa maneno mengine, hii ni mfano kamili ya wapi unataka kuhakikisha

844
00:50:10,400 --> 00:50:13,590
kwamba wote wa taarifa hizi za kutokea au si wakati wote

845
00:50:13,590 --> 00:50:15,450
kwa sababu vinginevyo mteja ni kwenda kupata Star

846
00:50:15,450 --> 00:50:17,670
na wewe ni kwenda kuchukua fedha zao na si mahali pengine amana,

847
00:50:17,670 --> 00:50:20,470
au benki ni kwenda kupata Star ambapo utaenda, hukuiweka fedha

848
00:50:20,470 --> 00:50:23,140
lakini si kweli Ondoa ni kutoka akaunti ya mtumiaji.

849
00:50:23,140 --> 00:50:25,810
Kwa hiyo unataka wote wawili na nitafanya pamoja.

850
00:50:25,810 --> 00:50:29,140
Hivyo inaingia katika shughuli dunia.

851
00:50:29,140 --> 00:50:31,360
Basi hiyo ni kitu kuweka katika nyuma ya akili yako,

852
00:50:31,360 --> 00:50:34,710
sio sana kwa madhumuni ya mradi tu wa mwisho,

853
00:50:34,710 --> 00:50:36,700
lakini kama unataka kuchukua mradi wako wa mwisho mahali fulani,

854
00:50:36,700 --> 00:50:39,040
kama unataka kuanzisha baadhi ya kampuni ya karibu yake,

855
00:50:39,040 --> 00:50:41,270
kama unataka kutatua tatizo baadhi ya kundi mwanafunzi juu ya chuo

856
00:50:41,270 --> 00:50:45,210
na kweli kuwa hai, hai tovuti, hizi ni aina ya mende Mpole kwamba yanaweza kutokea

857
00:50:45,210 --> 00:50:49,480
kama huna kabisa kufikiri kwa nini inaweza kutokea kama watu 2

858
00:50:49,480 --> 00:50:54,190
ni kujaribu kupata tovuti yako kwa wakati huo katika muda halisi,

859
00:50:54,190 --> 00:50:56,890
ambapo maswali yao ili vinginevyo kupata interwoven.

860
00:50:58,840 --> 00:51:01,420
>> Tayari kwa baadhi JavaScript, teaser yake?

861
00:51:01,420 --> 00:51:04,320
Hii ni lugha yetu ya mwisho kwa muhula. Wote haki.

862
00:51:04,320 --> 00:51:09,940
Nashiriki, JavaScript inaonekana sana, sana, sana sawa na lugha 2, C na PHP,

863
00:51:09,940 --> 00:51:11,140
tumefanya hivi sasa.

864
00:51:11,140 --> 00:51:14,340
Hakuna JavaScript katika pset 7, lakini ni chombo muhimu incredibly

865
00:51:14,340 --> 00:51:18,840
linapokuja kufanya mtandao msingi miradi ya mwisho au kweli tu mtandao programu kwa ujumla zaidi.

866
00:51:18,840 --> 00:51:20,950
Hivyo maelezo ya haraka ya kitu kinachoitwa DOM.

867
00:51:20,950 --> 00:51:23,600
Hapa ni super rahisi mtandao ukurasa kwamba kweli tu anasema hello, dunia

868
00:51:23,600 --> 00:51:25,970
wote katika cheo na katika mwili.

869
00:51:25,970 --> 00:51:29,270
Kama indentation amekuwa akipendekeza kwa muda fulani,

870
00:51:29,270 --> 00:51:31,380
kuna shaka Hierarkia kwa kurasa za mtandao.

871
00:51:31,380 --> 00:51:34,220
Mimi naweza kuchora snippet hiyo ya HTML kama mti,

872
00:51:34,220 --> 00:51:37,470
Tafakari kwa majadiliano yetu ya miundo data katika C, kama ifuatavyo.

873
00:51:37,470 --> 00:51:40,710
Mimi na baadhi maalum mzizi nodi kuitwa nodi hati,

874
00:51:40,710 --> 00:51:43,650
na tutaweza kuona Analog ya hili katika JavaScript katika muda tu.

875
00:51:43,650 --> 00:51:48,330
mtoto wa kwanza na mtoto tu ya kwamba katika kesi hii ni tag HTML.

876
00:51:48,330 --> 00:51:49,880
Hakuna ramani moja kwa moja ya doctype.

877
00:51:49,880 --> 00:51:53,170
Hiyo ni kitu maalum, hivyo sisi lazima tu kupuuza linapokuja hii DOM,

878
00:51:53,170 --> 00:51:55,810
hii Object Kudhibiti Model mti.

879
00:51:55,810 --> 00:51:59,530
Ona kwamba HTML tag, ambayo nimekuwa depicted kiholela kama mstatili,

880
00:51:59,530 --> 00:52:02,890
ana watoto 2: kichwa na mwili.

881
00:52:02,890 --> 00:52:04,840
>> Wale ni vile vile kama inayotolewa mistatiri.

882
00:52:04,840 --> 00:52:08,970
Ni ya maana pictorially kwamba kichwa ni upande wa kushoto wa mwili.

883
00:52:08,970 --> 00:52:11,960
Kidokezo ni kwamba kichwa huja kwanza katika mti.

884
00:52:11,960 --> 00:52:14,910
Hivyo kuna kweli kuagiza kwa mti wakati kuteka ni kama hii,

885
00:52:14,910 --> 00:52:17,460
ingawa maumbo na whatnot ni holela.

886
00:52:17,460 --> 00:52:20,360
Mkuu wakati huo huo ana mtoto mmoja aitwaye cheo,

887
00:52:20,360 --> 00:52:25,170
na cheo kweli ina mtoto wake mwenyewe, ambayo ni "hello, dunia",

888
00:52:25,170 --> 00:52:32,210
ambayo mimi kwa makusudi akauchomoa kama Oval hapa kufanya ni tofauti kidogo kutoka mstatili.

889
00:52:32,210 --> 00:52:37,420
Haya ni mambo mistatili, ambapo hello, dunia ni kweli nodi maandishi.

890
00:52:37,420 --> 00:52:39,850
Hivyo ni nodi katika mti, lakini ni aina tofauti ya nodi

891
00:52:39,850 --> 00:52:41,730
hivyo mimi akauchomoa kiholela tofauti.

892
00:52:41,730 --> 00:52:45,000
Vile vile haina mwili na mtoto aitwaye hello, dunia kama vile,

893
00:52:45,000 --> 00:52:47,910
hivyo tofauti nodi ingawa wao ni bahati Nakala huo,

894
00:52:47,910 --> 00:52:52,100
lakini nimekuwa inayotolewa kwa kutumia umbo moja. Hivyo ambaye anajali?

895
00:52:52,100 --> 00:52:56,820
Naam, ni nini kizuri kuhusu HTML ni kwamba ni gani hii asili kihierarkia.

896
00:52:56,820 --> 00:53:01,010
Na nini kizuri kuhusu JavaScript na maktaba hasa kwamba ni hiari inapatikana

897
00:53:01,010 --> 00:53:07,120
na maarufu kama jQuery, unaweza navigate muundo mti hivyo kushangaza rahisi.

898
00:53:07,120 --> 00:53:11,790
Yoyote ya mambo sisi alivyofanya katika C na kuyatumia na miti na traversing recursing juu ya nodes

899
00:53:11,790 --> 00:53:15,300
kushoto mtoto kwa mtoto wa kulia, kwa ghafla tunaweza aina ya kuchukua kwa nafasi

900
00:53:15,300 --> 00:53:19,450
kama kuwa kushangaza mwangaza kama si kidogo frustrating

901
00:53:19,450 --> 00:53:22,470
lakini si karibu njia bora ya kwenda kuhusu programu.

902
00:53:22,470 --> 00:53:24,470
Na hivyo kwa hizi ngazi za juu lugha kama JavaScript

903
00:53:24,470 --> 00:53:28,340
tutaweza kuwa na uwezo navigate mti huu zaidi intuitively.

904
00:53:28,340 --> 00:53:30,430
>> Na hakika syntax ni kwenda kuwa familiar kabisa.

905
00:53:30,430 --> 00:53:32,950
Kama wewe sijawahi kuona JavaScript kabla, hii ni kumbukumbu ya kweli nice

906
00:53:32,950 --> 00:53:35,910
kutoka folks Mozilla, watu ambao kufanya Firefox,

907
00:53:35,910 --> 00:53:38,370
hivyo kujisikia huru na kuvinjari kwamba kwa urahisi.

908
00:53:38,370 --> 00:53:41,590
Nini utapata - na hizi slides ni kufanana na kile sisi kutumika siku nyingine -

909
00:53:41,590 --> 00:53:44,030
vile vile, kuu ni gone.

910
00:53:44,030 --> 00:53:47,010
Hivyo wakati wewe kuandika mpango katika JavaScript, hakuna kazi kuu.

911
00:53:47,010 --> 00:53:48,690
Wewe tu kuanza kuandika code.

912
00:53:48,690 --> 00:53:51,660
Lakini tofauti muhimu kati ya JavaScript na C na PHP

913
00:53:51,660 --> 00:53:55,890
ni kwamba wakati ambapo C na PHP hivi sasa wamenyongwa server upande

914
00:53:55,890 --> 00:53:59,180
na appliance katika kesi hii au zaidi kwa ujumla na server,

915
00:53:59,180 --> 00:54:04,270
JavaScript kwa kubuni ni kawaida kunyongwa kwa browser.

916
00:54:04,270 --> 00:54:08,440
Kwa maneno mengine, unaweza kuandika JavaScript code, kama sisi ni juu ya,

917
00:54:08,440 --> 00:54:13,080
kwenye server katika appliance, lakini wewe ni pamoja na hiyo kati ya HTML yako, kati ya CSS yako,

918
00:54:13,080 --> 00:54:16,100
kati ya GIFs yako na PNGs yako na JPEGs yako

919
00:54:16,100 --> 00:54:19,170
hivyo kwamba wakati mtumiaji ziara mtandao wako ukurasa, kama wewe ni kutumia JavaScript,

920
00:54:19,170 --> 00:54:21,770
kwamba code JavaScript huja kutoka server browser,

921
00:54:21,770 --> 00:54:24,540
na ni kweli kwamba browser executes yake.

922
00:54:24,540 --> 00:54:27,960
Hivyo hii ina maana ya maana kwa ajili ya mali hata miliki.

923
00:54:27,960 --> 00:54:32,600
Ni aina ya silly hata kufikiri kuhusu kulinda IP yako linapokuja JavaScript code

924
00:54:32,600 --> 00:54:37,560
kwa sababu kwa asili ya lugha ya anapata kunyongwa kawaida browser upande.

925
00:54:37,560 --> 00:54:40,360
>> Unaweza obfuscate yake, ambayo ina maana unaweza kufanya ni kuangalia mambo na ugly

926
00:54:40,360 --> 00:54:45,400
na hakuna whitespace, kutisha variable majina, kwa kufanya ni vigumu kwa watu kuiba IP yako,

927
00:54:45,400 --> 00:54:48,120
lakini muhimu ni kwamba ni kunyongwa browser upande.

928
00:54:48,120 --> 00:54:51,790
Hata ingawa kama upande kando JavaScript inaweza kutumika server,

929
00:54:51,790 --> 00:54:54,480
matumizi ya kawaida kesi hivi sasa bado ni browser.

930
00:54:54,480 --> 00:54:59,800
Na hapa ni nini inaonekana kama. Hapa ni kama-kama-mwingine mwingine kujenga tu kama C, kama PHP.

931
00:54:59,800 --> 00:55:02,420
Hapa ni kujieleza Boolean wakati wewe "au" mambo 2 pamoja.

932
00:55:02,420 --> 00:55:04,330
Hapa ni wakati wewe "na" mambo 2 pamoja.

933
00:55:04,330 --> 00:55:08,300
Hapa ni taarifa kubadili, ambayo ni sawa na PHP

934
00:55:08,300 --> 00:55:10,810
katika kwamba unaweza kubadili kwa aina mbalimbali za maadili.

935
00:55:10,810 --> 00:55:15,180
Matanzi vile vile kuwa kwa matanzi hapa, ambayo ni muundo identically kwa nini tumekuwa kuona mbele.

936
00:55:15,180 --> 00:55:18,110
Wakati matanzi; tumekuwa got kufanya wakati matanzi.

937
00:55:18,110 --> 00:55:20,290
Vigezo, milele hivyo tofauti kidogo.

938
00:55:20,290 --> 00:55:24,560
Huwezi kutangaza vigezo kama wewe kufanya katika PHP na C,

939
00:55:24,560 --> 00:55:27,860
lakini vile vile ni JavaScript weakly typed.

940
00:55:27,860 --> 00:55:32,730
Huwezi kutaja int au kuelea au kamba au kitu kama hicho kwa kawaida.

941
00:55:32,730 --> 00:55:34,240
Unaweza kutaja var.

942
00:55:34,240 --> 00:55:38,040
Huna kutaja var, lakini ina maana kama huna.

943
00:55:38,040 --> 00:55:42,000
Kwa kawaida kama wewe omit var, ajali kujenga variable kimataifa badala ya mitaa.

944
00:55:42,000 --> 00:55:46,420
Hivyo basi mimi kupendekeza kwamba wewe daima karibu tu kusema var na kisha jina la kutofautiana.

945
00:55:46,420 --> 00:55:48,740
Ni si aina, ni tu var kwa kutofautiana.

946
00:55:48,740 --> 00:55:52,930
Hii itakuwa mfano, kama ni 123 au "hello, dunia".

947
00:55:52,930 --> 00:55:58,910
Arrays ni sasa na syntactically sawa na PHP.

948
00:55:58,910 --> 00:56:03,690
Mimi itabidi kusema idadi var na kisha mimi kutumia mabano mraba tena kutangaza variable

949
00:56:03,690 --> 00:56:08,870
ambao ni aina safu ambayo ina idadi haya hasa katika hilo kutengwa kwa koma.

950
00:56:08,870 --> 00:56:11,740
Na kisha mwisho, hii ni moja tu kwamba kweli inaonekana tofauti.

951
00:56:11,740 --> 00:56:16,700
Kumbuka kwamba katika PHP sisi ingekuwa kutekelezwa safu associative kwa mwanafunzi

952
00:56:16,700 --> 00:56:20,220
kama Zamyla kwamba ili kuangalia kama hii, ambapo variable inaitwa mwanafunzi.

953
00:56:20,220 --> 00:56:23,370
mabano mraba maana hiyo inakuja safu.

954
00:56:23,370 --> 00:56:28,500
>> ukweli kwamba mimi si kutumia fahirisi numeric lakini masharti - id, nyumba, na jina -

955
00:56:28,500 --> 00:56:30,990
ina maana kwamba hii ni safu associative,

956
00:56:30,990 --> 00:56:34,490
na haya mishale na alama ya usawa na bracket angled

957
00:56:34,490 --> 00:56:37,310
ina maana kwamba muhimu ni "id", thamani ni 1;

958
00:56:37,310 --> 00:56:39,310
muhimu ni "nyumba", thamani ni Winthrop Nyumba;

959
00:56:39,310 --> 00:56:41,800
muhimu ni "jina", thamani ni Zamyla Chan.

960
00:56:41,800 --> 00:56:47,110
Hivyo kuna 3 funguo ndani ya safu hii associative, ambayo kila mmoja ana thamani yake mwenyewe.

961
00:56:47,110 --> 00:56:52,880
Tumeona kwamba katika pset 7, au hivi karibuni mapenzi, katika JavaScript wazo moja,

962
00:56:52,880 --> 00:56:55,220
lakini ni kwenda kuangalia kama hii.

963
00:56:55,220 --> 00:57:00,070
Hivyo var mwanafunzi - hakuna ishara ya dola na bila kutaja aina bado lakini var -

964
00:57:00,070 --> 00:57:05,860
sawa na kisha kufungua braces curly kwa sababu katika JavaScript wakati una jozi thamani muhimu,

965
00:57:05,860 --> 00:57:08,900
wewe kweli matumizi ya kitu kinachoitwa kitu.

966
00:57:08,900 --> 00:57:13,490
Na wale ambao hawakuwa kuchukua APCS au kama anaweza kukumbuka vitu kutoka Java

967
00:57:13,490 --> 00:57:15,140
au lugha zinazofanana.

968
00:57:15,140 --> 00:57:17,880
JavaScript si Java, kwanza ya yote.

969
00:57:17,880 --> 00:57:21,600
Ilikuwa makusudi kubuni uamuzi miaka iliyopita na kubisha mbali kitu kingine kwamba alikuwa maarufu,

970
00:57:21,600 --> 00:57:25,640
jina lake, hata kama hana uhusiano msingi kwa java yenyewe.

971
00:57:25,640 --> 00:57:31,490
JavaScript ina vitu, na wewe kujenga nao kwa njia ya nukuu brace curly.

972
00:57:31,490 --> 00:57:36,710
Vitu katika JavaScript ni kiasi pretty sawa na arrays associative katika PHP

973
00:57:36,710 --> 00:57:40,030
linapokuja data hifadhi ndani mwao.

974
00:57:40,030 --> 00:57:44,100
>> Lakini hata kwa nguvu zaidi katika JavaScript unaweza kujiunga kwa urahisi sana kazi

975
00:57:44,100 --> 00:57:48,040
ndani ya kitu, na ingawa unaweza kufanya hivyo katika lugha nyingine,

976
00:57:48,040 --> 00:57:50,040
ni kabisa dhana ya kawaida, kama tutaweza kuona.

977
00:57:50,040 --> 00:57:54,380
Kwa kifupi, kitu hii inawakilisha mwanafunzi, ambaye ni hasa Zamyla,

978
00:57:54,380 --> 00:58:00,380
na ni sawa conceptually, tu syntactically tofauti na hii.

979
00:58:00,380 --> 00:58:03,840
Hebu kweli matumizi JavaScript katika faili.

980
00:58:03,840 --> 00:58:05,570
Ni zinageuka kuna tag script.

981
00:58:05,570 --> 00:58:08,180
Tumeona tag style na tumeona tags nyingine HTML.

982
00:58:08,180 --> 00:58:11,510
tag script kweli yana baadhi code JavaScript.

983
00:58:11,510 --> 00:58:15,500
Hebu kwenda katika appliance ambapo tuna baadhi code chanzo kabla ya kufanywa.

984
00:58:15,500 --> 00:58:18,700
Mimi si posted bado kwenye tovuti, lakini mimi itabidi kufanya hivyo baada ya darasa.

985
00:58:18,700 --> 00:58:21,770
Hebu kufungua hii moja, blink.html.

986
00:58:21,770 --> 00:58:27,560
Nyuma katika miaka ya 1990, kulikuwa na literally tag HTML kuitwa tag blink,

987
00:58:27,560 --> 00:58:30,340
na hii ilikuwa ni moja ya vitambulisho wengi ajabu overused kwenye mtandao

988
00:58:30,340 --> 00:58:36,140
ambapo wewe d kutembelea baadhi ya 1990 style mtandao ukurasa na kuanza kuona Nakala flashing wewe kama hii,

989
00:58:36,140 --> 00:58:39,810
matokeo ya tag Marquis, ambayo alikuwa Nakala kwenda kama hii.

990
00:58:39,810 --> 00:58:45,070
Moja ya mara chache ambapo dunia kweli walikubaliana juu ya kiwango mtandao,

991
00:58:45,070 --> 00:58:48,250
kila mtu katika bodi kuuawa tag blink baadhi ya miaka iliyopita.

992
00:58:48,250 --> 00:58:52,860
Lakini tunaweza kufufua kwa JavaScript kama maandamano ya nguvu una

993
00:58:52,860 --> 00:58:56,660
wakati unaweza kuandika mpango ndani ya ukurasa wa mtandao.

994
00:58:56,660 --> 00:59:00,240
Kwanza hebu ruka juu ya mambo mapya na lengo tu juu ya zamani.

995
00:59:00,240 --> 00:59:01,780
>> Hapa ni mambo ya zamani katika mfano huu.

996
00:59:01,780 --> 00:59:06,350
Nina tag HTML, tag kichwa, na tag cheo.

997
00:59:06,350 --> 00:59:11,210
Basi nina tag mwili hapa kwa div, ambayo ni wanakumbuka tu mgawanyiko pembenne ya ukurasa

998
00:59:11,210 --> 00:59:14,720
kwamba Nimekupa ID kipekee kiholela ya "salamu" kwa,

999
00:59:14,720 --> 00:59:18,320
hivyo tu nina njia ya kipekee akimaanisha yake, ambayo ina baadhi ya maandishi rahisi sana:

1000
00:59:18,320 --> 00:59:20,220
hello, ulimwengu.

1001
00:59:20,220 --> 00:59:23,940
Sasa basi mimi kitabu hadi juu ya faili hii na kuona nini mpya.

1002
00:59:23,940 --> 00:59:27,710
Jambo la kwanza kwamba mpya juu juu ni tag script,

1003
00:59:27,710 --> 00:59:31,280
na ndani ya taarifa tag script nimekuwa alitangaza kazi.

1004
00:59:31,280 --> 00:59:34,610
Kutangaza kazi katika JavaScript, pretty sawa na PHP,

1005
00:59:34,610 --> 00:59:37,930
wewe literally kuandika kazi basi jina la kazi mabano,

1006
00:59:37,930 --> 00:59:40,400
na labda baadhi ya hoja kama inachukua yoyote.

1007
00:59:40,400 --> 00:59:43,510
Kisha mimi nimepata brace yangu curly kama kawaida, na sasa tuna baadhi code kidogo mpya,

1008
00:59:43,510 --> 00:59:45,230
lakini hebu angalia hii ina maana gani.

1009
00:59:45,230 --> 00:59:48,670
Hivyo div var, hii ina maana tu nipe variable inayoitwa div.

1010
00:59:48,670 --> 00:59:50,530
Ningeweza kuitwa ni foo, lakini mimi alitaka kuitwa div

1011
00:59:50,530 --> 00:59:52,620
kwa sababu hiyo itakuwa wazi katika pili.

1012
00:59:52,620 --> 00:59:57,480
Kisha zinageuka katika JavaScript - na hii ni JavaScript code iliyoingia katika mtandao ukurasa wangu -

1013
00:59:57,480 --> 01:00:01,760
kuna maalum wa kimataifa wa aina variable iitwayo waraka.

1014
01:00:01,760 --> 01:00:04,780
JavaScript kwa kweli ni lugha ya kifaa-oriented.

1015
01:00:04,780 --> 01:00:07,230
Sisi si kuingia kwa undani katika 50 kama yale kwamba maana,

1016
01:00:07,230 --> 01:00:11,180
lakini kwa sasa kujua kwamba kitu ni pretty kiasi kama struct.

1017
01:00:11,180 --> 01:00:14,740
Kama tuliona njia ya nyuma wakati katika moja ya tatizo mwanzo seti

1018
01:00:14,740 --> 01:00:17,150
ambapo sisi kuweka mengi ya habari katika struct,

1019
01:00:17,150 --> 01:00:21,330
vile vile ni hati struct maalum ambayo inakuja na kivinjari,

1020
01:00:21,330 --> 01:00:24,810
kuja na ukurasa mtandao yoyote. Ni si kitu mimi kuundwa.

1021
01:00:24,810 --> 01:00:28,210
Ndani ya muundo huu hati, ingawa, una data si tu

1022
01:00:28,210 --> 01:00:30,010
lakini pia una kazi.

1023
01:00:30,010 --> 01:00:34,090
>> Na wakati wowote una kazi ndani ya muundo, ndani ya kifaa,

1024
01:00:34,090 --> 01:00:36,490
ni kuitwa mbinu. Lakini ni kitu kimoja.

1025
01:00:36,490 --> 01:00:40,110
Njia ni kazi ambayo tu hivyo hutokea kuwa ndani ya kitu kingine.

1026
01:00:40,110 --> 01:00:42,990
Hivyo hii ina maana kwamba hii maalum variable kimataifa iitwayo waraka

1027
01:00:42,990 --> 01:00:47,690
ina kazi kuitwa getElementById kwamba literally anafanya hivyo.

1028
01:00:47,690 --> 01:00:52,460
Ni kupata wewe kipengele kutoka DOM, Kudhibiti Object Model mti,

1029
01:00:52,460 --> 01:00:55,520
ambao ni ID katika salamu kesi hii.

1030
01:00:55,520 --> 01:00:59,200
Kwa maneno mengine, wakati wote sisi alitumia juu ya miundo ya data anakuja katika kucheza hapa.

1031
01:00:59,200 --> 01:01:01,400
Hii picha ya DOM kwamba tulikuwa na wakati uliopita,

1032
01:01:01,400 --> 01:01:06,100
ingawa ukurasa ni kidogo tofauti, kama alikuwa div katika picha hii,

1033
01:01:06,100 --> 01:01:11,180
nini document.getElementById atarudi kwangu ingekuwa na kuwa pointer

1034
01:01:11,180 --> 01:01:15,440
kwa Mstatili katika mti, akimaanisha Mstatili katika mti.

1035
01:01:15,440 --> 01:01:18,410
Basi hiyo ni nini maana ya kweli piga moja ya kazi hizo.

1036
01:01:18,410 --> 01:01:21,960
Katika kesi hii tena ni div. Ni si mwili au jina.

1037
01:01:21,960 --> 01:01:26,480
Basi hebu angalia nini mimi kufanya na kisha div hii sasa kwamba mimi ni ndani ya hii div variable kuitwa.

1038
01:01:26,480 --> 01:01:32,580
Ni zinageuka na JavaScript una uwezo wa tweak CSS yako ukurasa wa dynamically.

1039
01:01:32,580 --> 01:01:39,060
Hadi sasa, wote wa CSS tumefanya, angalau mdogo, ni katika sifa style,

1040
01:01:39,060 --> 01:01:41,730
au mahali pengine ambapo kuwa sisi kuweka CSS?

1041
01:01:42,730 --> 01:01:45,810
Mimi aina ya kuharibiwa kwamba moja. Katika tag style ya wakati juu ya faili.

1042
01:01:45,810 --> 01:01:49,180
Au nafasi ya tatu imekuwa katika?

1043
01:01:50,710 --> 01:01:54,590
>> faili nje, kitu css..

1044
01:01:54,590 --> 01:01:56,730
Basi hizo sehemu 3 tumefanya CSS hivi sasa,

1045
01:01:56,730 --> 01:01:59,310
lakini samaki ni ngumu tumekuwa coded yote.

1046
01:01:59,310 --> 01:02:04,060
Wewe aliamua kama wewe njiwa katika pset 7, tuliamua kabla hotuba nini CSS yetu itakuwa.

1047
01:02:04,060 --> 01:02:07,380
Lakini kama unataka kubadilisha CSS yako, unaweza kweli kufanya hivyo

1048
01:02:07,380 --> 01:02:09,370
mara moja una halisi ya programu lugha.

1049
01:02:09,370 --> 01:02:13,910
CSS, HTML - si programu lugha. JavaScript ni.

1050
01:02:13,910 --> 01:02:18,200
Hivyo ni zinageuka kuwa haraka kama una moja ya mistatiri wale kutoka mti

1051
01:02:18,200 --> 01:02:23,050
kuitwa DOM, ina yenyewe baadhi ya data ndani yake.

1052
01:02:23,050 --> 01:02:27,820
Hivyo div kwamba mimi tu grabbed kutoka mti ina nini Tutamwita mali ndani yake

1053
01:02:27,820 --> 01:02:34,390
kuitwa style, na mali style ina yenyewe mali inayoitwa kujulikana.

1054
01:02:34,390 --> 01:02:37,330
Ningependa kujua hii tu kwa kuangalia juu ya mwongozo user CSS ya.

1055
01:02:37,330 --> 01:02:41,160
Ni zinageuka kuna muonekano CSS mali ambayo haina nini anasema.

1056
01:02:41,160 --> 01:02:44,530
Ni hufanya kitu inayoonekana au la, inayoonekana au la.

1057
01:02:44,530 --> 01:02:46,810
Na jinsi ya kufanya kwamba ni hii.

1058
01:02:46,810 --> 01:02:50,510
Mimi nauliza programmatically ikiwa muonekano wa div hii ni siri,

1059
01:02:50,510 --> 01:02:53,390
nini mimi kuibadilisha kwa? Inayoonekana.

1060
01:02:53,390 --> 01:02:58,840
Mwingine kama muonekano wa ukurasa huu si siri, mantiki mimi kufanya hivyo siri.

1061
01:02:58,840 --> 01:03:04,070
Mimi sielewi kwa nini ni inayoonekana na siri na si vinavyoonekana na visivyoonekana.

1062
01:03:04,070 --> 01:03:06,000
Hii ilikuwa maskini kubuni uamuzi njiani.

1063
01:03:06,000 --> 01:03:09,530
Lakini hayo ni kweli kinyume katika CSS: inayoonekana na siri.

1064
01:03:09,530 --> 01:03:15,520
Yote hii haina maana ni kubadili CSS ya faili yangu na mbali, na mbali

1065
01:03:15,520 --> 01:03:16,870
kwa kuwa div fulani.

1066
01:03:16,870 --> 01:03:20,630
Lakini tena, hii ni kazi kuitwa blink. Wakati ni kazi blink wito?

1067
01:03:20,630 --> 01:03:24,080
Ni zinageuka kuwa kuna mwingine maalum wa kimataifa variable kuitwa dirisha,

1068
01:03:24,080 --> 01:03:28,220
sawa katika roho na waraka huo, lakini wakati hati inahusu mtandao ukurasa wako,

1069
01:03:28,220 --> 01:03:31,700
kama mti DOM, HTML wewe alimtuma kutoka server,

1070
01:03:31,700 --> 01:03:35,250
dirisha inahusu chrome karibu yake, anwani bar, bar cheo,

1071
01:03:35,250 --> 01:03:37,880
na yote ya kwamba mambo kote mtandao ukurasa wako.

1072
01:03:37,880 --> 01:03:42,800
>> Na zinageuka kuwa kitu dirisha ina kazi maalum ndani yake aitwaye setInterval

1073
01:03:42,800 --> 01:03:44,360
kwamba anafanya nini anasema.

1074
01:03:44,360 --> 01:03:48,600
Itakuwa kuweka Interval - katika kesi hii kila milliseconds 500 -

1075
01:03:48,600 --> 01:03:52,270
na, kuchukua nadhani, nini ni kwenda kufanya kila milliseconds 500?

1076
01:03:52,270 --> 01:03:55,240
Ni kwenda nitafanya kwamba blink kazi.

1077
01:03:55,240 --> 01:03:58,560
Na nini ni nzuri hapa ni kwamba sisi wangefanya hii katika C ingawa sisi kamwe alifanya.

1078
01:03:58,560 --> 01:04:01,580
C gani kuwa kitu kinachoitwa kazi kuyatumia ambapo unaweza kupita kazi kuzunguka

1079
01:04:01,580 --> 01:04:03,140
kama hoja.

1080
01:04:03,140 --> 01:04:07,620
Vile vile katika JavaScript unaweza kupita jina la kazi katika kazi nyingine.

1081
01:04:07,620 --> 01:04:10,630
Na taarifa ya nini mimi kufanya. Mimi si kufanya hili.

1082
01:04:10,630 --> 01:04:14,380
Kama mimi kuweka mabano baada blink, kwamba ingekuwa na maana piga kazi blink.

1083
01:04:14,380 --> 01:04:17,430
Kama mimi omit yao, kwamba maana hapa ni kazi blink

1084
01:04:17,430 --> 01:04:21,330
hivyo setInterval kwamba wanaweza kumwita kila milliseconds 500.

1085
01:04:21,330 --> 01:04:28,200
Hivyo matokeo ya mwisho, ingawa mauaji ni, ni kwamba kama mimi kwenda katika kwenye localhost na kwenda blink.html,

1086
01:04:28,200 --> 01:04:32,120
Mimi sasa hili likitokea tena na tena.

1087
01:04:32,120 --> 01:04:34,950
Na kama mimi kwa kweli Kagua Element, hebu tuone kama tunaweza kuona hayo.

1088
01:04:34,950 --> 01:04:38,550
Hebu Kagua Element, basi mimi kitabu chini kidogo tu,

1089
01:04:38,550 --> 01:04:44,320
basi mimi kuchagua Elements zaidi ya hapa, na ilani ndani ya DOM ya mkaguzi Chrome.

1090
01:04:44,320 --> 01:04:48,840
Ni literally kubadilisha na kurudi milliseconds kila 500.

1091
01:04:48,840 --> 01:04:55,660
Kama sisi kwenda kwa rafiki yetu Nate,

1092
01:04:55,660 --> 01:05:00,020
kama umewahi kujiuliza jinsi hii ni kazi, sawa na wazo Interval,

1093
01:05:00,020 --> 01:05:04,810
lakini Nate ni kweli kufanya ufanisi sana matumizi ya alama katika kesi hii hapa.

1094
01:05:04,810 --> 01:05:07,350
Basi nini zaidi tunaweza kweli kufanya na hili?

1095
01:05:07,350 --> 01:05:09,990
Hebu kufungua mfano mwingine na kujaribu kitu

1096
01:05:09,990 --> 01:05:12,940
hiyo ni programmatically hata muhimu zaidi kuliko kufanya mambo blink.

1097
01:05:12,940 --> 01:05:17,990
Hebu kwenda katika directory yetu fomu leo ​​na kwenda katika form0.

1098
01:05:17,990 --> 01:05:20,820
Hii ilikuwa fomu ugliest inawezekana kwamba mimi naweza kuja na,

1099
01:05:20,820 --> 01:05:23,290
na napenda tu kuonyesha nini inaonekana kama katika browser.

1100
01:05:23,290 --> 01:05:28,960
>> Hebu kwenda kwenye localhost / fomu, na hii ni form0.

1101
01:05:28,960 --> 01:05:33,400
Hii ni super ugly HTML fomu kuwa ana mashamba chache kwa barua pepe, kwa password,

1102
01:05:33,400 --> 01:05:37,190
password, na kisha tiki kidogo kwa kukubaliana na masharti ya baadhi na masharti.

1103
01:05:37,190 --> 01:05:41,350
catch ni kama mimi kutembelea fomu hii na sitaki kukupa yangu ya barua pepe,

1104
01:05:41,350 --> 01:05:44,730
Sitaki kukubaliana na masharti na sheria labda, naweza bonyeza Register

1105
01:05:44,730 --> 01:05:46,920
na inakuwezesha yangu kwa njia ya anyway.

1106
01:05:46,920 --> 01:05:50,800
Hii hutokea kwa kuwasilisha faili kijinga PHP kuitwa dump.php.

1107
01:05:50,800 --> 01:05:58,420
All yake ni magazeti nje ya yaliyomo ya $ _GET tu kwa madhumuni ya uchunguzi.

1108
01:05:58,420 --> 01:06:01,580
Hiyo ilikuwa ni nini in kwa mtumiaji tu sasa.

1109
01:06:01,580 --> 01:06:05,010
Lakini tuseme sisi kweli unataka kuhalalisha aina ya mtumiaji kuwasilisha.

1110
01:06:05,010 --> 01:06:06,530
Hebu kwenda katika toleo 1.

1111
01:06:06,530 --> 01:06:11,420
Hii ni form1.html. Inaonekana aesthetically kama mbaya, lakini taarifa jinsi dhana ni.

1112
01:06:11,420 --> 01:06:15,450
Kama mimi bonyeza Register bila kushirikiana, mimi kupata yelled saa.

1113
01:06:15,450 --> 01:06:17,320
"Lazima kutoa anuani yako ya barua pepe."

1114
01:06:17,320 --> 01:06:21,670
Wote haki. Hivyo basi mimi kujaribu kuwa. Hivyo malan@harvard.edu. Sihitaji password.

1115
01:06:21,670 --> 01:06:25,100
Register. "Lazima kutoa password." Wote haki.

1116
01:06:25,100 --> 01:06:28,470
Hivyo mimi kutoa password ya rangi nyekundu. Register.

1117
01:06:28,470 --> 01:06:32,300
"Nywila hayaoani." Mimi sasa hapa aina katika nyekundu.

1118
01:06:32,300 --> 01:06:35,710
Mimi ajali checked kwamba. Register.

1119
01:06:35,710 --> 01:06:39,860
"Wewe lazima kukubaliana na masharti na sheria." Wote haki. Kukubaliana huko. Register.

1120
01:06:39,860 --> 01:06:43,700
Na sasa inaonyesha mimi pato uchunguzi zaidi ya hapo.

1121
01:06:43,700 --> 01:06:45,630
>> Basi nini ilitokea tu?

1122
01:06:45,630 --> 01:06:48,330
Tulikuwa na uwezo huu ili adhibitishe maoni fomu.

1123
01:06:48,330 --> 01:06:51,420
Kwa kweli, kama alivyofanya kupiga mbizi katika pset 7, kuna kazi Apologize

1124
01:06:51,420 --> 01:06:54,620
kwamba inafanya pretty rahisi yell katika user kwa ujumbe kwenye screen.

1125
01:06:54,620 --> 01:06:57,580
Mimi nina kutumia utaratibu tofauti kidogo, kazi tahadhari,

1126
01:06:57,580 --> 01:07:03,690
ambayo si kazi hiyo alitabasamu juu tangu inafanya ujumbe user sana ugly.

1127
01:07:03,690 --> 01:07:05,710
Lakini hebu angalia nini mimi kufanya hapa.

1128
01:07:05,710 --> 01:07:09,620
Hii ni form1.html, na taarifa kwamba mimi na baadhi ya syntax pretty familiar:

1129
01:07:09,620 --> 01:07:12,920
mwili tag, fomu tag, hatua sifa, njia sifa.

1130
01:07:12,920 --> 01:07:17,050
Lakini taarifa Nimekupa fomu yangu ID kipekee kwa urahisi.

1131
01:07:17,050 --> 01:07:19,190
Kisha mimi nimepata email shamba ambaye ni aina ya maandishi,

1132
01:07:19,190 --> 01:07:23,780
shamba password ambaye ni aina ya nywila, uthibitisho shamba ambaye ni aina ya nywila,

1133
01:07:23,780 --> 01:07:28,070
na kisha tiki ambaye jina lake ni makubaliano juu hapa, aina ni checkbox.

1134
01:07:28,070 --> 01:07:30,380
Na kisha mimi nimepata kifungo kuwasilisha.

1135
01:07:30,380 --> 01:07:33,050
Lakini taarifa juu nini zaidi nina.

1136
01:07:33,050 --> 01:07:35,810
Awali ya yote, kuna mwingine matumizi ya tag script.

1137
01:07:35,810 --> 01:07:40,520
Kama una baadhi code JavaScript katika faili mwingine, kama tu na CSS unaweza ni pamoja na hiyo.

1138
01:07:40,520 --> 01:07:44,530
Na wewe kufanya hivyo kwa chanzo script, na kisha taarifa mimi nina kuunganisha inaonekana

1139
01:07:44,530 --> 01:07:50,349
kwa googleapis.com kwa njia ya muda mrefu sana lakini faili ambaye jina inaishia katika jquery.min

1140
01:07:50,349 --> 01:07:52,420
kwa kiwango cha chini JS..

1141
01:07:52,420 --> 01:07:55,969
jQuery ni super maarufu maktaba kwa JavaScript kwamba tu hufanya JavaScript

1142
01:07:55,969 --> 01:07:58,230
zaidi ya yote user-kirafiki kutumia.

1143
01:07:58,230 --> 01:08:00,610
Ni kwa ufanisi kuwa kiwango de facto.

1144
01:08:00,610 --> 01:08:04,090
Hivyo hata kama nini wewe kuhusu kuona si safi JavaScript per se,

1145
01:08:04,090 --> 01:08:09,340
ni maktaba juu ya JavaScript kiasi kama maktaba CS50 ni safu

1146
01:08:09,340 --> 01:08:13,670
juu ya ngazi ya chini code C; ukweli ni karibu kila mtu kwenye mtandao anatumia hiyo.

1147
01:08:13,670 --> 01:08:18,030
Hivyo haya si mafunzo ya magurudumu. Hii ni bora mazoezi siku hizi.

1148
01:08:18,030 --> 01:08:22,830
Sasa taarifa chini ya kwamba ni script wangu mwenyewe tag, na taarifa ya kile nimepata kufanyika hapa.

1149
01:08:22,830 --> 01:08:27,450
Ni zinageuka kuwa jQuery haina kitu dhana kidogo.

1150
01:08:27,450 --> 01:08:29,660
JavaScript ina ishara ya dola, lakini wao ni maana.

1151
01:08:29,660 --> 01:08:32,870
>> Wao ni kama barua B au au C.

1152
01:08:32,870 --> 01:08:36,670
jQuery ina tu iliyopitishwa mkataba au aina ya madai aliweka na ukweli

1153
01:08:36,670 --> 01:08:40,280
kwamba dola itakuwa alama yao maalum.

1154
01:08:40,280 --> 01:08:44,950
Hivyo kwa haraka kama wewe kupakia hii ya kimataifa JavaScript faili hapa juu na tag script,

1155
01:08:44,950 --> 01:08:49,080
unaweza kupata variable maalum ya kimataifa kwamba wito $.

1156
01:08:49,080 --> 01:08:53,009
Ni vizuri zaidi kuitwa jQuery, lakini hiyo haina kuangalia karibu kama sexy kama $.

1157
01:08:53,009 --> 01:08:56,250
Lakini $ hana maana maalum. Katika PHP ilikuwa maana maalum.

1158
01:08:56,250 --> 01:08:58,440
Ilikupasa kuwa ni mbele ya kutofautiana.

1159
01:08:58,440 --> 01:09:01,670
Hii ni kitu sexy kwamba wao alichukua.

1160
01:09:01,670 --> 01:09:03,389
Ni nini kinachoendelea hapa?

1161
01:09:03,389 --> 01:09:08,830
Taarifa mimi nina kupita kwa kazi jQuery variable wangu kimataifa hati

1162
01:09:08,830 --> 01:09:10,860
na kisha mimi nina wito tayari..

1163
01:09:10,860 --> 01:09:15,480
Nini jQuery kimsingi haina ni utapata kuchukua baadhi ya mambo JavaScript vanilla

1164
01:09:15,480 --> 01:09:17,889
kama kitu hati, kitu dirisha,

1165
01:09:17,889 --> 01:09:20,790
na kama wewe kupita katika kufanya kazi jQuery -

1166
01:09:20,790 --> 01:09:24,429
na tena, kwa kuwa wazi, hii ni kazi kuitwa jQuery -

1167
01:09:24,429 --> 01:09:28,240
kile yake ni kuirudisha kwa wewe toleo maalum ya hati

1168
01:09:28,240 --> 01:09:30,700
ambayo ina zaidi ya utendaji yanayohusiana na hayo.

1169
01:09:30,700 --> 01:09:34,760
Hivyo katika JavaScript ghafi hakuna kazi tayari,

1170
01:09:34,760 --> 01:09:37,810
lakini kama wewe kupita hati kwa kazi jQuery kwanza,

1171
01:09:37,810 --> 01:09:40,960
kuirudisha kwa wewe toleo maalum ya kitu hati

1172
01:09:40,960 --> 01:09:43,030
ambayo ina makala zaidi dhana.

1173
01:09:43,030 --> 01:09:48,230
Na kwamba ni kwa nini watu kama hiyo. Ni tu hufanya mambo rahisi kufanya, kama sisi ni juu ya kuona.

1174
01:09:48,230 --> 01:09:49,820
Hiyo ni nini hii maana ya mstari wa kanuni?

1175
01:09:49,820 --> 01:09:52,690
Hii mstari wa kanuni hapa ina maana wakati hati tayari -

1176
01:09:52,690 --> 01:09:56,830
kwa maneno mengine, mara moja browser inafanywa kusoma hii ya juu faili chini -

1177
01:09:56,830 --> 01:09:59,200
kwenda mbele na kutekeleza kazi zifuatazo.

1178
01:09:59,200 --> 01:10:03,540
Nini kweli kuvutia katika JavaScript - na PHP ina hii pia -

1179
01:10:03,540 --> 01:10:05,450
ni anonymous kazi.

1180
01:10:05,450 --> 01:10:10,560
Katika JavaScript unaweza kutangaza kazi ya kwamba hawana jina lakini wao kuwa na mwili.

1181
01:10:10,560 --> 01:10:12,570
Angalia kinachotokea hapa.

1182
01:10:12,570 --> 01:10:16,220
>> Hii ni kazi kuitwa tayari, na ni njia tu kufanya yafuatayo

1183
01:10:16,220 --> 01:10:20,220
wakati wote mtandao ukurasa ni tayari, wakati ni wote wamekuwa kusoma katika kutoka kwa seva.

1184
01:10:20,220 --> 01:10:23,090
Nini unataka kufanya nini? Nataka nitafanya chunk ya code.

1185
01:10:23,090 --> 01:10:27,120
Ona kwamba hatutaki kutekeleza kanuni hii haki ya mbali.

1186
01:10:27,120 --> 01:10:34,350
Kama mimi omitted hii, hii itamaanisha kuanza utekelezaji mara moja mistari haya ya kificho.

1187
01:10:34,350 --> 01:10:39,040
Lakini ukweli kwamba mimi kusema hapana, hapana, hapana, wrap hii katika kazi bila majina kama hii

1188
01:10:39,040 --> 01:10:43,000
njia wala nitafanya hivyo bado, simu yake hatimaye.

1189
01:10:43,000 --> 01:10:45,430
Tuliona huu iliyopita katika mfano wetu uliopita fomu.

1190
01:10:45,430 --> 01:10:49,990
Nini kazi gani sisi kuwaita hatimaye, 500 milliseconds baadaye? Blink.

1191
01:10:49,990 --> 01:10:51,480
Hivyo wazo moja.

1192
01:10:51,480 --> 01:10:53,950
Tena, hata kama hii inaonekana kidogo weird, tu kuchukua kwa sasa juu ya imani

1193
01:10:53,950 --> 01:10:57,060
kwamba kutangaza kazi bila majina kwamba wito hatimaye,

1194
01:10:57,060 --> 01:11:01,720
wewe tu kuandika kazi () {

1195
01:11:01,720 --> 01:11:05,380
Basi nini code ni sisi kwenda nitafanya hatimaye? zifuatazo.

1196
01:11:05,380 --> 01:11:10,460
Hii pia inaonekana mpya kidogo, lakini hii ina maana hapa kazi jQuery,

1197
01:11:10,460 --> 01:11:13,430
na hii sasa ni njia ya mkato.

1198
01:11:13,430 --> 01:11:18,830
Hii snippet ya HTML chini ya screen ya shaka ina baadhi ya uwakilishi mti.

1199
01:11:18,830 --> 01:11:21,730
Siyo hii. Ukarasa huu ni ya kuvutia zaidi kuliko mfano huu hello, ulimwengu.

1200
01:11:21,730 --> 01:11:25,210
Lakini kuna baadhi ya mti kwamba sambamba na HTML hii.

1201
01:11:25,210 --> 01:11:28,910
Itakuwa maumivu katika shingo ya kuwa na kutekeleza baadhi ya aina ya kazi ya kujirudia

1202
01:11:28,910 --> 01:11:34,380
kuanza nodi katika mizizi na kisha kupata nodi ambaye ni ID usajili.

1203
01:11:34,380 --> 01:11:38,340
Basi nini jQuery hufanya super rahisi kwetu ni halisi huu.

1204
01:11:38,340 --> 01:11:43,000
Kwenda mbele na kupata yangu chochote div au fomu chochote, chochote HTML kipengele

1205
01:11:43,000 --> 01:11:45,820
ana ID ya usajili.

1206
01:11:45,820 --> 01:11:52,440
Hii ni sawa na document.getElementById ('usajili').

1207
01:11:52,440 --> 01:11:54,170
>> Kwa nini watu kama jQuery?

1208
01:11:54,170 --> 01:12:00,110
Sababu ni mfupi kwa aina. Lakini hiyo yote ni. Ni wazo moja.

1209
01:12:00,110 --> 01:12:02,630
Kupata yangu tag ambao ID ni usajili.

1210
01:12:02,630 --> 01:12:06,300
Na wakati tag kwamba, ambayo hufanyika kuwa fomu, ni in,

1211
01:12:06,300 --> 01:12:08,300
kwenda mbele na kutekeleza kanuni hii.

1212
01:12:08,300 --> 01:12:11,320
Basi hebu kuchukua moja kuangalia sasa jinsi sisi ni kufanya aina validation.

1213
01:12:11,320 --> 01:12:15,950
syntax ni admittedly cryptic mara ya kwanza, lakini nini kinaendelea?

1214
01:12:15,950 --> 01:12:21,050
Kama hii mstari wa kanuni ni kweli, mimi nina kwenda yell katika user kutoa yake anuani ya barua pepe.

1215
01:12:21,050 --> 01:12:22,970
Hivyo ni nini hii mstari wa kanuni?

1216
01:12:22,970 --> 01:12:25,560
$ Maana jQuery. Sasa taarifa hii.

1217
01:12:25,560 --> 01:12:27,920
Hii ni aina ya kama CSS.

1218
01:12:27,920 --> 01:12:33,370
Kama umefanya dived katika CSS bado, utajua kwamba hii ina maana ya kipengele ambao ID ni usajili.

1219
01:12:33,370 --> 01:12:39,840
nafasi ina maana kupata mtoto au mtoto wa usajili ambaye jina lake ni pembejeo.

1220
01:12:39,840 --> 01:12:42,970
Na kisha jambo hili katika mabano mraba ni chujio kidogo.

1221
01:12:42,970 --> 01:12:47,010
Na hata kama hii inaonekana cryptic, hii ina maana kwenda kwa ajili ya ambao ID ni usajili,

1222
01:12:47,010 --> 01:12:51,230
kwenda ndani ya pembejeo kipengele cha kwamba ambaye jina lake ni barua pepe,

1223
01:12:51,230 --> 01:12:55,440
na kisha kupata thamani yake, chochote thamani yake hutokea kwa kuwa -

1224
01:12:55,440 --> 01:12:59,670
asdf kama kwamba ni yote Mimi typed au malan@harvard.edu kama kwamba ni nini mimi typed.

1225
01:12:59,670 --> 01:13:05,250
Hivyo kama thamani ya shamba barua pepe aina ya kitu ==, yell katika mtumiaji.

1226
01:13:05,250 --> 01:13:09,700
Mwingine kama thamani ya shamba password == kitu, yell katika mtumiaji.

1227
01:13:09,700 --> 01:13:19,520
>> Mwingine kama thamani ya shamba password haina sawa thamani ya shamba uthibitisho,

1228
01:13:19,520 --> 01:13:22,850
ambayo ilikuwa nyingine aina ya kipengele, yell katika mtumiaji.

1229
01:13:22,850 --> 01:13:25,680
Na kisha mwisho - na moja hii pia ina baadhi syntax mpya ya peke yake,

1230
01:13:25,680 --> 01:13:29,270
lakini mara ve kuona hilo, ni angalau kidogo zaidi ya busara -

1231
01:13:29,270 --> 01:13:34,060
mwingine kama fomu ambao ni ID usajili ina kipengele pembejeo ambaye jina lake ni makubaliano

1232
01:13:34,060 --> 01:13:39,720
na ni checked, kwenda mbele na yell katika mtumiaji.

1233
01:13:39,720 --> 01:13:42,520
Kwa hiyo mimi kabisa kukubali hii ni balaa kabisa katika mtazamo wa kwanza.

1234
01:13:42,520 --> 01:13:46,530
Ni mengi ya syntax mpya. Lakini yote ya jQuery ifuatavyo aina hii ya ruwaza.

1235
01:13:46,530 --> 01:13:49,880
Na kwa uaminifu, sikuweza hata kujua hii ulikuwepo mpaka dakika chache zilizopita.

1236
01:13:49,880 --> 01:13:53,640
Mimi Googled, "Je, wewe kuangalia kama checkbox ni checked katika jQuery?"

1237
01:13:53,640 --> 01:13:55,680
na hii ni syntax, kwa sababu kuna njia tofauti za kufanya hivyo

1238
01:13:55,680 --> 01:13:58,010
na halisi code ghafi JavaScript.

1239
01:13:58,010 --> 01:14:01,030
Hivyo kama ukurasa sana kwanza ya tatizo Set 7 inasisitiza,

1240
01:14:01,030 --> 01:14:04,500
pset 7 ni mengi sana katika zoezi uchangishaji mwenyewe

1241
01:14:04,500 --> 01:14:08,650
ambapo tumekuwa zinazotolewa, hopefully, mfumo wa dhana ambayo kukabiliana pset.

1242
01:14:08,650 --> 01:14:12,280
>> Lakini kama ni mara ya kesi pamoja na kubuni mtandao, ni juu kweli poke kote,

1243
01:14:12,280 --> 01:14:16,680
kuingiza snippets ya maadili na mifano kutoka Mtandao muda mrefu kama wewe wanaelezea yao

1244
01:14:16,680 --> 01:14:17,960
kwa masharti juu ya karatasi ya kwanza,

1245
01:14:17,960 --> 01:14:21,460
na kutambua kwamba kujifunza HTML, CSS, JavaScript na hata SQL

1246
01:14:21,460 --> 01:14:26,020
ni kweli maana ya kuwa zoezi hili katika-nyumbani kama sisi kuanza kuchukua magurudumu haya mafunzo mbali.

1247
01:14:26,020 --> 01:14:29,150
Na kutambua pia kuna mengi zaidi ya mambo unaweza kufanya kwa browser.

1248
01:14:29,150 --> 01:14:33,790
Ndani ya zaidi ya mambo haya kuna mambo mengine aitwaye tukio handlers.

1249
01:14:33,790 --> 01:14:37,140
Na hata kama sisi alimwangalia ndio inayoitwa onsubmit na onready,

1250
01:14:37,140 --> 01:14:40,310
unaweza kufanya mambo kama onkeydown, onkeyup,

1251
01:14:40,310 --> 01:14:43,410
kama wakati mtumiaji linagusa muhimu, unaweza kusikiliza kwa kuwa na up muhimu.

1252
01:14:43,410 --> 01:14:45,940
Gmail ina keyboard shortcuts.

1253
01:14:45,940 --> 01:14:49,490
Jinsi gani Google kutekeleza keyboard shortcuts kama C kwa kutunga?

1254
01:14:49,490 --> 01:14:54,120
Wao kusikiliza kwa matukio, kama uko wito, kama onkeypress au onkeyup na onkeydown.

1255
01:14:54,120 --> 01:14:56,360
Kama ve milele hovered mouse yako juu ya chaguo baadhi menu

1256
01:14:56,360 --> 01:15:00,180
na ghafla, voilà, menu inaonekana au graphic mabadiliko Michezo,

1257
01:15:00,180 --> 01:15:01,920
jinsi wanafanya hivyo?

1258
01:15:01,920 --> 01:15:06,940
Badala ya kusikiliza kwa onready au onsubmit, wewe kusikiliza kwa onmouseover au onmouseout.

1259
01:15:06,940 --> 01:15:10,920
>> Hivyo katika muda mfupi, na shemu hizi rahisi sana kwamba tumeanza kwa scratch ya uso wa leo

1260
01:15:10,920 --> 01:15:13,940
na tutaweza kupiga mbizi katika zaidi juu ya Jumatano, una, inazidi,

1261
01:15:13,940 --> 01:15:17,530
uwezo wa kutekeleza aina ya mambo ambayo tayari wewe ni ukoo na.

1262
01:15:17,530 --> 01:15:21,620
Basi hebu mwisho huko, na tutaweza kuendelea hii juu ya Jumatano.

1263
01:15:22,690 --> 01:15:24,320
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