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>> [Daqq tal-mużika]

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DAVID Malan: Kull dritt, dan huwa CS50.

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Dan huwa l-aħħar ta 'tmien ġimgħat.

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00:00:13,740 --> 00:00:15,887
U llum, nibdew
biex timla xi biċċiet

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meta niġu għall-bini
affarijiet fuq il-web.

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00:00:17,720 --> 00:00:20,020
Allura, ifakkar li nhar it-Tnejn
nonfqu ħafna aktar ħin

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fuq PHP, li huwa dan dinamiku
lingwa ta 'programmar li

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tikri us output, fost oħrajn
affarijiet, HTML u kontenut ieħor bħal

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li aħna ser trid tara.

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Iżda aħna ma verament ħares lejn kif
aħna qed tmur biex jaħżnu kwalunkwe informazzjoni.

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Tabilħaqq, kważi xi li l super
websajts interessanti li żżur illum

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għandhom xi tip ta 'database
fuq il-aħħar lura, id-dritt?

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Facebook ċertament taħżen lottijiet ta 'data
dwar lkoll u mħażen Gmail kollha

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ta 'emails tiegħek.

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>> U għalhekk, bosta siti oħra mhumiex biss
kontenut statiku li l informattivi.

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Huwa fil-fatt dinamika b'xi mod.

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Inti tipprovdi input, taġġorna
il-paġni għal nies oħra.

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Ikollok messaġġi, inti tibgħat
messaġġi, u oħrajn.

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Hekk illum, aħna qrib lejn
l-irfid ta 'proġett

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li inti ser adsa fis jmiss
ġimgħa, CS50 Finanzi, li

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huwa attwalment se jkollhom inti tibni
xi ħaġa mhux C, iżda fil-PHP.

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A website li jistenna
ftit xi ħaġa bħal din

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li jippermetti li jixtru u jbiegħu
istokkijiet li huma attwalment

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ser timxi fuq ħin reali
dejta ta 'stokk minn Yahoo Finanzi.

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U għalhekk finalment, inti ser ikollok l-
illużjoni għalik innifsek u għall-utenti

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li int fil-fatt jixtru u jbiegħu
ħażniet u jkollna ħin kważi reali

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aġġornamenti, ġestjoni ta '
portafoll, li kollha

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se jeħtieġu li,
finalment, database ta 'utenti.

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>> Allura, fi kliem tiegħek,
speċjalment jekk int ma

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super familjari mal-kompjuter
xjenza jew databases, liema

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do you know database li tkun
dritt issa, f'termini nontechnical?

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X'inhu dan?

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Kif tiddeskrivi lilha
għal roommate jew xi ħabib?

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>> UDJENZA: [inaudible]
informazzjoni [inaudible]

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>> DAVID Malan: Allura, lista ta 'informazzjoni,
jew store-- lista ta 'informazzjoni

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li inti tista 'tixtieq li taħżen
dwar xi ħaġa, bħal utent.

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U liema do utenti jkollhom
assoċjati magħhom?

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Jekk int utent fuq Facebook jew
Gmail, liema huma l-karatteristiċi

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li lkoll utenti jkollhom?

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Bħal, x'jista 'jkun xi wħud mill-
kolonni fil-spreadsheet li aħna

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allużjoni aħħar darba?

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Minħabba darb'oħra, inti tista '
think ta 'database

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verament bħala fancy fajl Excel jew Google
Spreadsheet jew Apple Numri fajl.

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>> Allura, x'taħseb ta
meta taħseb ta 'utent?

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What do huma għandhom?

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Dak X'inhu?

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>> UDJENZA: A isem.

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>> DAVID Malan: A isem.

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Mela jekk isem, bħal, David Malan
tkun l-isem ta 'xi utent.

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X'iktar ma l-utent għandhom?

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>> UDJENZA: An ID.

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>> DAVID Malan: An ID.

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Allura, bħal numru ta 'identifikazzjoni, bħal Harvard tiegħek
ID jew Yale ID Net tiegħek jew bħalhom.

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X'iktar jista utent għandhom?

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>> UDJENZA: Password.

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>> DAVID Malan: A password, forsi
indirizz, forsi numru tat-telefon, forsi

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email address.

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Allura, hemm għenieqed ta 'oqsma u dan
tista tip ta 'spirali barra mill-kontroll

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malajr malli tibda
twettiq, oh, ejja taħżen din

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u ejja jaħżnu dan u li.

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>> Imma kif nistgħu fil-fatt jagħmlu dan?

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Għalhekk għal darb'oħra, il-mudell mentali
li jkollhom għal-lum kif aħna

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adsa fis SQL attwali,
Strutturat Mistoqsija Lingwa,

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hija database li tidher bħal dan.

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Huwa biss ringieli u kolonni.

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U inti tista 'timmaġina Google ispreadsheets
jew kwalunkwe numru ta 'programmi oħra.

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Imma x'hemm prinċipali dwar MySQL, li hija l-
softwer tad-database aħna qed tmur għall-użu,

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l apertament liberament
available-- użi Facebook

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u kull numru ta 'websites-- oħra
database jaħżen affarijiet relationally.

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U database relazzjonali
ifisser biss wieħed li litteralment

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imħażen tad-data tiegħu fir-ringieli u kolonni.

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Huwa sempliċi bħal dik.

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>> Għalhekk, anki xi ħaġa bħal Oracle li
inti jista 'jkollok ġeneralment jinstemgħu ta'

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hija database relazzjonali.

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U taħtha il-barnuża, huwa
jaħżen data fir-ringieli u kolonni.

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U Oracle tariffi inti
ħafna flus biex jagħmlu dan,

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billi tariffi MySQL
inti xejn għall-istess.

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Allura, SQL se tagħtina
mill-anqas erba 'operazzjonijiet.

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Il-ħila li tagħżel data, bħal read
data, daħħal, tħassar, u taġġorna data.

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Fi kliem ieħor, dawn huma
verament l-erba 'operazzjonijiet ewlenin

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li ser inessu bidla
Jittieħed f'dawk ringieli u kolonni.

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>> L-għodda li aħna ser tuża llum speċjalment
biex jitgħallmu SQL u jilagħbu magħha

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terġa tissejjaħ MyAdmin PHP.

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Huwa web għodda bbażata.

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Koinċidenza Total li
Huwa bil-miktub fil-PHP.

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Iżda li għaddej biex tagħtina grafika
user interface sabiex inkunu nistgħu attwalment

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joħolqu dawn ringieli u kolonni
u mbagħad tkellem lilhom permezz kodiċi.

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Allura, ejja issa tibda
dak li naħseb huwa franchement

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tip tal-proċess gost ta '
bini tal-aħħar lura ta 'websajts,

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il-partijiet li l-utenti ma jagħmlux dan
tara, iżda b'mod kostanti jagħmlu kura dwar,

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għaliex dan huwa pjuttost ta 'data għaddej.

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Allura, simili għal C u
ftit inqas bħal PHP,

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SQL, jew database li jappoġġja
SQL, għandha tipi tal-anqas din id-data

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u għenieqed ta 'oħrajn.

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CHAR, varchar, INT, BIGINT,
Deċimali, u dateTime.

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U hemm ħaġa waħda
mazz ta 'fatturi oħra,

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imma ejja tagħmel dan billi
Bħala eżempju attwali.

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>> Jien se jmorru fil CS50 IDE
fejn, bil-quddiem, stajt illoggjat

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u Stajt ukoll żar URL għall
din l-għodda msejħa PHP MyAdmin.

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U fil-problema stabbiliti seba ', aħna ser jgħidlek
inti eżattament kif tikseb din l-interfaċċa

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kif ukoll.

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Min-rokna ta 'fuq tax-xellug,
Avviż jgħid lecture.

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U dan ifisser biss li
bil-quddiem, I ħolqot

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database imsejħa lecture vojta
li m'għandha l-ebda spreadsheets fil encore.

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M'hemm l-ebda ringieli u kolonni.

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Minħabba li l-ewwel
Ħaġa aħna qed tmur biex tagħmel

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huwa tibda biex joħolqu tabella
li għaddej biex jaħżnu utenti tagħna.

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>> Allura, litteralment fuq
hawn lejn il-lemin, jien

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ser jgħidlek-database
Irrid tabella msejħa Utenti.

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Allura, dan huwa bħall-fajl li I
tixtieq li taħżen kollha ta 'data tiegħi fil.

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U kemm kolonni?

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Well, ejja jżommha sempliċi għal issa.

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I biss tixtieq li taħżen bħal
username u l-isem għall-utent.

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Aħna ser tibda żgħar.

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So, I tixtieq żewġ kolonni totali.

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U jien ser jimxi 'l quddiem u kklikkja Go.

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U mbagħad, għal dawn
kolonni, dak li jien ser

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biex do-- jekk dan internet
cooperates-- id-dritt,

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hekk aħna qed tmur biex tipprova li għal darb'oħra.

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Jien ser tinħoloq tabella msejħa
Utenti b'żewġ kolonni, ikklikkja Go, OK.

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Issa konna ltqajna verament mgħaġġel.

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Grazzi, tajjeb ħafna isir.

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Kull dritt, hekk dak li irridu
dawn il-kolonni li għandu jissejjaħ?

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>> Għalhekk, wieħed għaddej biex jiġu msejħa Username.

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Allura, kollha nara here-- u l-interface
franchement gets ftit ikrah eventwalment,

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ladarba tibda ittajpjar f'dan data kollha.

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Imma x'hemm sbieħ huwa li tip ta '
paradossalment, jien ħolqien kolonni,

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iżda l-għodda għandha foolishly
stabbiliti minnhom fir-ringieli

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sabiex I tista 'tikkonfigura dawn il-kolonni.

131
00:05:31,560 --> 00:05:33,550
Allura, hemm żewġ blanks taħtu Isem.

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U waħda minn dawn l-oqsma I
tixtieq li jissejjaħ Username,

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u l-qasam oħra nixtieq li sejħa Isem.

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>> U issa I għandhom jagħżlu
tipi ta 'data għal dawn l-affarijiet.

135
00:05:40,340 --> 00:05:42,330
Allura, filwaqt li fl-Excel
u Spreadsheets Google,

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jekk inti tixtieq kolonna, inti litteralment
biss it-tip Isem jew Username, hit Ikteb.

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00:05:45,531 --> 00:05:48,030
Forsi inti tagħmel dan wiċċ bold
biss għaċ-ċarezza, iżda li dan.

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Inti ma jispeċifikawx il-
tipi tal-kolonni.

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00:05:50,140 --> 00:05:53,790
Issa fil Google Spreadsheets jew Excel, inti
jista tispeċifika kif id-data hija mogħtija.

140
00:05:53,790 --> 00:05:58,120
Inti tista 'tmur għall-menu Format, u inti
tista 'tispeċifika juru dan is-sinjal dollaru simili,

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juru dan bħal valur b'punt li jvarja.

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>> Għalhekk, huwa simili fl-ispirtu li
li dak li aħna qed waslu biex jagħmlu,

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00:06:01,990 --> 00:06:04,740
iżda dan huwa attwalment għaddejjin seħħ
id-data li tkun ċertu tip.

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00:06:04,740 --> 00:06:07,750
Issa, anki jekk mument ilu I
qal hemm tipi ta 'data biss ftit,

145
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hemm attwalment
lott kollu, u dawn qed

146
00:06:11,120 --> 00:06:12,910
fi gradi ta 'speċifiċità li jvarjaw.

147
00:06:12,910 --> 00:06:14,970
U bħala twarrib, inti
tista 'anki tagħmel affarijiet fancy

148
00:06:14,970 --> 00:06:17,520
bħal ġeometriji ħażna
ġewwa ta 'database.

149
00:06:17,520 --> 00:06:19,250
Inti jista 'jaħżen affarijiet
bħal GPS koordinati

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00:06:19,250 --> 00:06:22,420
u attwalment issib, matematikament,
punti li huma qrib lill-oħrajn.

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00:06:22,420 --> 00:06:24,128
Iżda aħna qed tmur biex
iżommu din super sempliċi

152
00:06:24,128 --> 00:06:26,800
u jitla 'sa hawn, kollha
l-hekk imsejħa tipi sekwenza.

153
00:06:26,800 --> 00:06:29,240
>> Allura, hawn lista ta '
mazz sħiħ ta 'għażliet.

154
00:06:29,240 --> 00:06:32,740
CHAR, varchar, TINYTEXT,
MEDIUMTEXT, LONGTEXT.

155
00:06:32,740 --> 00:06:34,110
U huwa tip ta 'kbira.

156
00:06:34,110 --> 00:06:37,610
U sfortunatament, xi ftit
paradossalment sa C,

157
00:06:37,610 --> 00:06:40,120
a CHAR mhuwiex verament CHAR.

158
00:06:40,120 --> 00:06:44,170
Jekk inti tispeċifika fid-database
dak it-tip tad-data tiegħek huwa CHAR,

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00:06:44,170 --> 00:06:47,390
dan ifisser li iva, huwa
CHAR, imma hija Chars wieħed jew aktar.

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00:06:47,390 --> 00:06:49,630
U għandek tispeċifika
kif Chars ħafna inti tixtieq.

161
00:06:49,630 --> 00:06:51,636
Allura, x'hemm tipiku
tul għal username?

162
00:06:51,636 --> 00:06:52,760
Hemm limitu tipikament?

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00:06:52,760 --> 00:06:53,920
>> UDJENZA: [inaudible]

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00:06:53,920 --> 00:06:55,050
>> DAVID Malan: 16 forsi?

165
00:06:55,050 --> 00:06:55,990
Xi haga hekk.

166
00:06:55,990 --> 00:06:57,948
You know, lura fil-
jum, li jintuża biex tkun tmienja.

167
00:06:57,948 --> 00:07:00,289
Xi kultant huwa 16, kultant
huwa saħansitra aktar minn dak.

168
00:07:00,289 --> 00:07:02,080
U għalhekk, dan ma
ifisser jagħtu me CHAR wieħed.

169
00:07:02,080 --> 00:07:04,730
Dan ifisser I biss għandhom jispeċifikaw
it-tul tal-qasam,

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00:07:04,730 --> 00:07:07,402
u issa I jista 'jgħid xi ħaġa simili 16.

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00:07:07,402 --> 00:07:08,610
U hemm kummerċ off hawn.

172
00:07:08,610 --> 00:07:11,360
Allura, aħna ser tara fil-mument
li dan ifisser wieħed,

173
00:07:11,360 --> 00:07:14,620
kull username għandu jkun 16 karattru.

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00:07:14,620 --> 00:07:18,720
Iżda stenna minuta, M-A-L-A-N. Jekk dan huwa
username tiegħi u jien biss jużaw ħames,

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00:07:18,720 --> 00:07:23,070
dak tipproponi li d-database
tagħmel għall-11 karattri oħra li

176
00:07:23,070 --> 00:07:24,471
Stajt riżervati spazju għall?

177
00:07:24,471 --> 00:07:25,220
X'taghmel?

178
00:07:25,220 --> 00:07:26,480
>> UDJENZA: [inaudible]

179
00:07:26,480 --> 00:07:27,160
>> DAVID Malan: Yeah, just
jagħmluhom kollha null.

180
00:07:27,160 --> 00:07:28,290
Jagħmluhom spazji.

181
00:07:28,290 --> 00:07:30,816
Iżda probabbilment null, so a
ħafna żerijiet backslash.

182
00:07:30,816 --> 00:07:33,190
Għalhekk, fuq naħa waħda, konna
issa għamel żgur li username tiegħi

183
00:07:33,190 --> 00:07:34,780
jistax ikun hemm aktar minn 16 karattru.

184
00:07:34,780 --> 00:07:37,590
U n-naħa flip ta 'dan huwa
li jekk kelli isem verament twila

185
00:07:37,590 --> 00:07:39,940
jew riedu verament twila
username bħal xi wħud minnkom

186
00:07:39,940 --> 00:07:44,840
guys jista 'jkollhom f'dik kulleġġ jew
fil Yale.edu, ma jistax ikollok wieħed.

187
00:07:44,840 --> 00:07:47,177
U għalhekk fil-fatt, jekk inti stajt
qatt irreġistrati għal websajt

188
00:07:47,177 --> 00:07:49,385
u ikollok għajjat ​​fil jgħidu
password tiegħek twil wisq

189
00:07:49,385 --> 00:07:52,710
jew username tiegħek twil wisq, huwa
sempliċement minħabba programmer, meta

190
00:07:52,710 --> 00:07:55,500
konfigurazzjoni database tiegħu jew tagħha,
li ddeċieda f'dan il-qasam se

191
00:07:55,500 --> 00:07:57,150
ikun itwal minn dan it-tul.

192
00:07:57,150 --> 00:08:00,580
>> Dritt kollox, jekk iva, liema
aħna tipproċedi biex insemmu?

193
00:08:00,580 --> 00:08:05,240
Kemm għandu jkun twil ta '
Isem tal-bniedem tipiku jkun?

194
00:08:05,240 --> 00:08:07,492
Kemm karattri, 16?

195
00:08:07,492 --> 00:08:09,450
Jien guessing nistgħu
issib xi ħadd f'din il-kamra

196
00:08:09,450 --> 00:08:13,210
fejn mill-ewwel plus tiegħu jew tagħha aħħar
isem huwa itwal minn 16 karattru.

197
00:08:13,210 --> 00:08:14,850
Allura, x'hemm aħjar minn dik, 17?

198
00:08:14,850 --> 00:08:17,040
18?

199
00:08:17,040 --> 00:08:18,830
25?

200
00:08:18,830 --> 00:08:20,350
Akbar?

201
00:08:20,350 --> 00:08:20,980
30?

202
00:08:20,980 --> 00:08:21,855
>> UDJENZA: [inaudible]

203
00:08:21,855 --> 00:08:23,700
DAVID Malan: 5000, oh Alla tiegħi.

204
00:08:23,700 --> 00:08:26,309
Allura, li probabbilment deċenti
ta 'fuq marbuta, nistgħu ngħidu.

205
00:08:26,309 --> 00:08:28,350
U hawn aħna tip ta 'jkollhom
tagħmel sejħa sentenza.

206
00:08:28,350 --> 00:08:30,400
Bħal, hemm ebda tweġiba t-tajba hawn.

207
00:08:30,400 --> 00:08:32,740
Infinita ma tantx huwa possibbli,
għaliex aħna qed eventwalment

208
00:08:32,740 --> 00:08:34,781
ser have-- aħna qed
ser jispiċċaw ta 'memorja.

209
00:08:34,781 --> 00:08:36,909
Allura, aħna għandna biex jagħmlu
sentenza sejħa f'xi punt.

210
00:08:36,909 --> 00:08:41,010
>> Komuni ħafna tkun, per eżempju,
li use-- u let me tispeċifika CHAR hawn

211
00:08:41,010 --> 00:08:46,050
kif before-- 255 kien litteralment il-
limitu massimu fuq dan is-software database

212
00:08:46,050 --> 00:08:46,700
snin ilu.

213
00:08:46,700 --> 00:08:48,575
U għalhekk, ħafna bnedmin
se biss jgħidu, multa.

214
00:08:48,575 --> 00:08:49,420
255 tal-limitu.

215
00:08:49,420 --> 00:08:50,620
Ejja biss jużaw il-massimu.

216
00:08:50,620 --> 00:08:51,870
U dan huwa pretty redikoli.

217
00:08:51,870 --> 00:08:55,060
Bħal, jekk int ittajpjar xi ħadd huwa
isem għal 200 karattru plus,

218
00:08:55,060 --> 00:08:56,140
li ftit redikola.

219
00:08:56,140 --> 00:08:59,624
>> Iżda, ftakar li ASCII mhuwiex
l-unika sistema għall-karattri.

220
00:08:59,624 --> 00:09:01,540
U għalhekk, speċjalment
Ħafna lingwi Asjatiċi

221
00:09:01,540 --> 00:09:04,248
fejn hemm karattri ma nistgħux
jesprimu fuq tastieri bħall-Istati Uniti tiegħi

222
00:09:04,248 --> 00:09:08,209
tastiera, xi karattri attwalment
jieħdu 16 bits minflok tmienja bits.

223
00:09:08,209 --> 00:09:10,250
U għalhekk, dan fil-fatt
mhux kollha li irraġonevoli

224
00:09:10,250 --> 00:09:12,250
li għandna bżonn aktar
ispazju jekk irridu li tajbin

225
00:09:12,250 --> 00:09:16,252
karattri akbar mill-Istati Uniti ħafna
dawk iċċentrati konna tendenza li jiddiskutu.

226
00:09:16,252 --> 00:09:17,460
Għalhekk, għandna bżonn xi rbit għoli.

227
00:09:17,460 --> 00:09:21,470
I do not know liema l-aħjar waħda hija,
iżda 255 huwa ġeneralment wieħed komuni.

228
00:09:21,470 --> 00:09:22,700
25 iħoss baxx.

229
00:09:22,700 --> 00:09:23,857
16, 32 tħoss baxx.

230
00:09:23,857 --> 00:09:25,690
Nixtieq żball fuq in-naħa
ta 'xi ħaġa ogħla.

231
00:09:25,690 --> 00:09:27,330
Iżda hemm kummerċ off, bħal dejjem.

232
00:09:27,330 --> 00:09:31,902
X'inhu l-, forsi, ovvju
kummerċ off li jiġi rriżervat 255 Chars

233
00:09:31,902 --> 00:09:33,360
għall-isem ta 'kulħadd fid-database tiegħi?

234
00:09:33,360 --> 00:09:34,230
>> UDJENZA: [inaudible]

235
00:09:34,230 --> 00:09:34,510
>> DAVID Malan: X'hemm li?

236
00:09:34,510 --> 00:09:35,430
>> UDJENZA: [inaudible]

237
00:09:35,430 --> 00:09:37,138
>> DAVID Malan: Huwa
lott ta 'memorja, right?

238
00:09:37,138 --> 00:09:42,280
M-A--L A-N. I għadek moħlija 250
karattri biss biex jaħżnu l-isem tiegħi

239
00:09:42,280 --> 00:09:46,000
defensively, biss fil-każ li xi ħadd
fil-klassi għandha isem verament twila.

240
00:09:46,000 --> 00:09:47,940
Li tidher qisha tradeoff żejjed.

241
00:09:47,940 --> 00:09:52,040
>> Allura, jirriżulta li SQL,
din il-lingwa database,

242
00:09:52,040 --> 00:09:55,480
fil-fatt jappoġġja xi ħaġa
imsejħa varchar, jew varjabbli CHAR.

243
00:09:55,480 --> 00:09:59,390
U dan huwa tip ta 'sbieħ f'dak dan
jippermettilek li tispeċifika mhux fiss

244
00:09:59,390 --> 00:10:01,900
wisa ', iżda, wisa varjabbli.

245
00:10:01,900 --> 00:10:05,060
U b'mod aktar speċifiku, ta '
wisa 'massima tal-qasam.

246
00:10:05,060 --> 00:10:08,901
Allura, dan ifisser li isem jista
tkun aktar minn 250 karattru,

247
00:10:08,901 --> 00:10:10,150
imma tista 'ċertament tkun inqas.

248
00:10:10,150 --> 00:10:11,733
U d-database se tkun intelliġenti.

249
00:10:11,733 --> 00:10:14,860
Jekk inti tpoġġi fil M-A-L-A-N,
huwa biss ser tuża ħames,

250
00:10:14,860 --> 00:10:18,120
forsi sitt bytes għall like
karattru null batuta,

251
00:10:18,120 --> 00:10:23,330
u ma jonfqu addizzjonali
249 jew 250 bytes bla bżonn.

252
00:10:23,330 --> 00:10:27,380
>> Allura, din tidher qisha I għandhom
bdew ma 'din l-istorja.

253
00:10:27,380 --> 00:10:29,140
Imma dejjem hemm tradeoff.

254
00:10:29,140 --> 00:10:33,024
Allura, min-naħa waħda, username stajt
speċifikat li tkun jsibuha ikkodifikat f'livell 16,

255
00:10:33,024 --> 00:10:34,940
u forsi li ma kienx
is-sejħa dritt, forsi

256
00:10:34,940 --> 00:10:40,040
huwa, iżda għaliex ma jużawx
VARCHARs għal kollox?

257
00:10:40,040 --> 00:10:42,020
>> Jeżisti għal raġuni.

258
00:10:42,020 --> 00:10:46,200
Għaliex ma jużawx VARCHARs għal kull qasam
li t-tul inti ma taf minn qabel

259
00:10:46,200 --> 00:10:48,180
jekk jidher li tkun ħaġa kbira, id-dritt?

260
00:10:48,180 --> 00:10:50,482
Uża biss kif spazju kemm
għandek bżonn sa dan il-limitu?

261
00:10:50,482 --> 00:10:51,271
>> UDJENZA: anqas mgħaġġel.

262
00:10:51,271 --> 00:10:52,146
DAVID Malan: speller?

263
00:10:52,146 --> 00:10:53,120
UDJENZA: Jagħmilha aktar bil-mod?

264
00:10:53,120 --> 00:10:53,970
DAVID Malan: Oh, huwa kajman.

265
00:10:53,970 --> 00:10:55,720
Tajba, li kważi dejjem
it-tweġiba, franchement.

266
00:10:55,720 --> 00:10:56,520
Bħal, x'inhu l-tradeoff?

267
00:10:56,520 --> 00:10:58,570
Hija la spejjeż aktar spazju
jew li l-ispejjeż aktar ħin.

268
00:10:58,570 --> 00:11:00,111
Allura, f'dan il-każ, jista 'jkun aktar bil-mod.

269
00:11:00,111 --> 00:11:00,920
Għaliex?

270
00:11:00,920 --> 00:11:05,830
>> UDJENZA: [inaudible]
determinazzjoni [inaudible].

271
00:11:05,830 --> 00:11:06,640
>> DAVID Malan: Tajba.

272
00:11:06,640 --> 00:11:09,670
Allura, inti tista 'recall minn anki
PSED5, playing mal-approċċ tiegħek

273
00:11:09,670 --> 00:11:12,750
għall-dizzjunarju, jekk għandek
jalloka memorja dinamikament jew iżommu

274
00:11:12,750 --> 00:11:14,630
tkabbir ta 'buffer, li
jista 'attwalment jiġi bil-mod.

275
00:11:14,630 --> 00:11:16,963
Jekk inti għandek sejħa malloc
taħt il-barnuża u forsi

276
00:11:16,963 --> 00:11:19,610
dan huwa dak MySQL qed tagħmel, hekk
żgur li jista 'jkun il-każ.

277
00:11:19,610 --> 00:11:22,430
U jekk taħseb mod
lura għall PSet-- jew saħansitra

278
00:11:22,430 --> 00:11:26,340
ġimgħat żewġ, affarijiet meta għamilna bħall
tfittxija binarju jew saħansitra tfittxija lineari,

279
00:11:26,340 --> 00:11:30,690
waħda mill-affarijiet sbieħ dwar kull kelma
f'database jew kull kelma fil-kolonna

280
00:11:30,690 --> 00:11:33,690
jkunu eżattament l-istess tul, anke
jekk mazz sħiħ ta 'dawk il-karattri

281
00:11:33,690 --> 00:11:37,390
huma vojta, hija li inti tista 'tuża
aċċess bl-addoċċ fuq data tiegħek, id-dritt?

282
00:11:37,390 --> 00:11:40,310
>> Jekk inti taf li kull
kelma hija 16 karattri bogħod,

283
00:11:40,310 --> 00:11:46,460
inti tista 'tuża aritmetika pointer, hekk li
jitkellmu, u mur lilna 16, 32, 48, 64,

284
00:11:46,460 --> 00:11:49,589
u inti tista 'biss jaqbżu
istantanjament billi jintuża aritmetika

285
00:11:49,589 --> 00:11:51,130
għal xi kliem fid-database tiegħek.

286
00:11:51,130 --> 00:11:54,280
Billi jekk huwa varchar,
dak li inti minflok tagħmel?

287
00:11:54,280 --> 00:11:55,960
>> [PHONE Żarżir]

288
00:11:55,960 --> 00:11:58,680
>> Jekk huwa varchar, inti
ma tistax tuża l-aċċess bl-addoċċ.

289
00:11:58,680 --> 00:12:01,341
Dak li għandek tfittex jew tagħmel?

290
00:12:01,341 --> 00:12:01,840
Yeah?

291
00:12:01,840 --> 00:12:03,240
>> UDJENZA: [inaudible]

292
00:12:03,240 --> 00:12:04,310
>> DAVID Malan: Ħares
permezz tal-traċċa whole--

293
00:12:04,310 --> 00:12:06,518
permezz tal-lista sħiħa
infittxu dak li, x'aktarx?

294
00:12:06,518 --> 00:12:08,356
X'tip ta 'valur speċjali?

295
00:12:08,356 --> 00:12:09,230
UDJENZA: [inaudible]

296
00:12:09,230 --> 00:12:11,105
DAVID Malan: Ħarsa
għall-Terminators nulla

297
00:12:11,105 --> 00:12:13,637
li jiddemarkaw s-separazzjoni ta 'kliem.

298
00:12:13,637 --> 00:12:15,720
Għalhekk għal darb'oħra, tradeoff, u
hemm ebda tweġiba t-tajba.

299
00:12:15,720 --> 00:12:18,380
Iżda din hija fejn, speċjalment
meta l-utenti tiegħek jiksbu jkunu differenti ħafna

300
00:12:18,380 --> 00:12:21,700
u t-tagħbija tiegħek fuq servers tiegħek, il-
numru ta 'nies li jużaw jiġrilha għolja,

301
00:12:21,700 --> 00:12:23,650
dawn huma attwalment deċiżjonijiet nontrivial.

302
00:12:23,650 --> 00:12:26,640
Allura, nistgħu tħalli dawn għax, iżda
ejja iscroll fuq il-lemin

303
00:12:26,640 --> 00:12:27,332
hawn.

304
00:12:27,332 --> 00:12:30,290
Issa, hemm koppja ta 'kolonni
fejn irridu nkunu sejħa sentenza.

305
00:12:30,290 --> 00:12:35,170
Jagħmel sens li jippermettu s utent
isem, username ta 'utent jew ta utent

306
00:12:35,170 --> 00:12:36,370
isem, li jkun null?

307
00:12:36,370 --> 00:12:37,610
Dan huwa, biss vojta.

308
00:12:37,610 --> 00:12:40,360
Iħoss ftit tagħmel sens, hekk jien
mhux se jiċċekkja dawn il-kaxxi.

309
00:12:40,360 --> 00:12:42,670
Iżda jirriżulta fi
database, inti tista 'tgħid,

310
00:12:42,670 --> 00:12:44,620
xi ħadd tista 'voluntarjament jkollhom dan il-valur.

311
00:12:44,620 --> 00:12:47,180
Din il-kolonna ma jkollux
li attwalment ikun hemm.

312
00:12:47,180 --> 00:12:48,570
>> Issa, hemm dan drop down menu.

313
00:12:48,570 --> 00:12:50,810
U avviż jien xorta
fl-ewwel filliera hemm,

314
00:12:50,810 --> 00:12:52,520
hekk jien jitkellem dwar username issa.

315
00:12:52,520 --> 00:12:56,290
U jirriżulta li database,
b'differenza sempliċi spreadsheet sempliċi,

316
00:12:56,290 --> 00:12:58,520
għandu l-karatteristiċi qawwija msejħa indiċijiet.

317
00:12:58,520 --> 00:13:02,600
U indiċi huwa mod ta 'javżak l-
database minn qabel li I l-bniedem

318
00:13:02,600 --> 00:13:03,900
am intelliġenti minn int.

319
00:13:03,900 --> 00:13:10,430
>> Naf liema tipi ta 'mistoqsijiet, tagħżel
jew daħħal jew tħassar jew taġġorna,

320
00:13:10,430 --> 00:13:13,182
dan il-kodiċi tiegħi se jispiċċaw
up tagħmel fuq id-database.

321
00:13:13,182 --> 00:13:14,390
Irrid li taqra ħafna ta 'data.

322
00:13:14,390 --> 00:13:15,681
Irrid li daħħal ħafna ta 'data.

323
00:13:15,681 --> 00:13:17,530
Irrid li kontinwament
tħassar ħafna ta 'data.

324
00:13:17,530 --> 00:13:21,520
Jekk Naf li jien ser tkun
aċċess qasam bħal Username ħafna,

325
00:13:21,520 --> 00:13:24,770
I tista 'tgħid l-preemptively
database, I taf aktar milli suppost,

326
00:13:24,770 --> 00:13:29,220
u nixtieq li digriet li
għandek indiċi f'dan il-qasam.

327
00:13:29,220 --> 00:13:33,200
Fejn indiċjar qasam jew kolonna
ifisser li d-database bil-quddiem

328
00:13:33,200 --> 00:13:37,040
għandu jissellef xi ideat minn, bħal,
ġimgħa erba 'u ħames u sitt persuni minn CS50

329
00:13:37,040 --> 00:13:39,240
u fil-fatt jibnu
xi ħaġa bħal tfittxija binarja

330
00:13:39,240 --> 00:13:41,560
siġra jew xi ħaġa
ġeneralment imsejħa siġra B

331
00:13:41,560 --> 00:13:43,410
li inti titgħallem
fil-CS124 bħal klassi

332
00:13:43,410 --> 00:13:46,710
fil-Harvard, klassi algoritmi,
jew kwalunkwe numru ta 'postijiet oħra.

333
00:13:46,710 --> 00:13:49,570
>> Id-database u l-smart
nies li implimentaw dan

334
00:13:49,570 --> 00:13:53,880
se figura kif taħżen
dik it-tabella ta 'informazzjoni

335
00:13:53,880 --> 00:13:57,061
fil-memorja sabiex tfittxijiet u
operazzjonijiet oħra huma super fast.

336
00:13:57,061 --> 00:13:58,060
Inti ma għandekx tagħmel dan.

337
00:13:58,060 --> 00:14:00,640
Inti ma għandekx biex jimplimentaw
tfittxija lineari jew tfittxija binarja

338
00:14:00,640 --> 00:14:03,300
jew jingħaqdu sort jew selezzjoni
sort, xi li.

339
00:14:03,300 --> 00:14:06,590
Id-database ma għalik jekk inti tgħid
dan preemptively indiċi f'dan il-qasam.

340
00:14:06,590 --> 00:14:09,100
>> U tista 'tara wisq, hemm
xi karatteristiċi oħra

341
00:14:09,100 --> 00:14:11,010
nistgħu tell-database li tinforza.

342
00:14:11,010 --> 00:14:16,431
Liema jista jfisser jekk I jagħżlu Unique
minn dan il-menu, biss intuwittivament?

343
00:14:16,431 --> 00:14:16,930
Yeah?

344
00:14:16,930 --> 00:14:17,889
>> UDJENZA: [inaudible]

345
00:14:17,889 --> 00:14:19,930
DAVID Malan: Yeah, il-
username għandu jkun uniku.

346
00:14:19,930 --> 00:14:23,330
Huwa dan ħaġa tajba jew ħaġa ħażina għal
database, għal websajt ma 'utenti?

347
00:14:23,330 --> 00:14:24,965
Jekk usernames jkun uniku?

348
00:14:24,965 --> 00:14:25,880
Yeah, probabbilment.

349
00:14:25,880 --> 00:14:27,800
Jekk dan huwa dak li l-
qasam nużaw biex login,

350
00:14:27,800 --> 00:14:31,867
inti ma verament irridu li persuni li jkollhom
l-istess jħossu jew l-istess username.

351
00:14:31,867 --> 00:14:33,700
Allura, jista 'jkollna l-
database jinfurzaw dik hekk

352
00:14:33,700 --> 00:14:37,880
li issa fil-kodiċi PHP tiegħi jew kwalunkwe lingwa,
I ma jkollhom, per eżempju, check

353
00:14:37,880 --> 00:14:41,490
neċessarjament ma dan username
jeżistu qabel I let reġistru xi ħadd?

354
00:14:41,490 --> 00:14:46,690
Id-database mhux se let żewġ persuni msemmija
David jew Malans jirreġistraw f'dan il-każ.

355
00:14:46,690 --> 00:14:50,030
>> U bħala twarrib, anke jekk din
menu biss ihallik tagħżel waħda,

356
00:14:50,030 --> 00:14:54,550
indiċi uniku huwa wieħed li l-
indiċjati għall-prestazzjoni super fast,

357
00:14:54,550 --> 00:14:56,100
iżda jinforza wkoll uniċità.

358
00:14:56,100 --> 00:14:58,850
U aħna ser terga 'lura għal dak l-
oħra żewġ jfissru fi ftit mument.

359
00:14:58,850 --> 00:15:00,930
Sadanittant, jekk immur
tieni ringiela tiegħi, li

360
00:15:00,930 --> 00:15:06,230
huwa l-isem tal-utent, għandi jispeċifika
li l-isem għandu jkun uniku?

361
00:15:06,230 --> 00:15:09,550
Le, għaliex inti tista 'ċertament
have-- hemm l-ebda tnejn David

362
00:15:09,550 --> 00:15:11,050
Malans f'din il-kamra, l-aktar probabbli.

363
00:15:11,050 --> 00:15:14,290
Imma jekk nagħżlu isem differenti,
nistgħu ċertament, ħabtiet.

364
00:15:14,290 --> 00:15:16,130
>> Think lura hash tabelli u simili.

365
00:15:16,130 --> 00:15:18,604
Allura, aħna żgur ma jridux
li jagħmlu l-qasam isem uniku.

366
00:15:18,604 --> 00:15:21,270
Allura, aħna qed biss ser jitilqu
li bħala sing, sing, sing, xejn.

367
00:15:21,270 --> 00:15:22,660
U jien ser jitilqu
kull ħaġa oħra biss.

368
00:15:22,660 --> 00:15:25,035
Tabilħaqq, ħafna minn dawn l-oqsma
aħna mhux se jkollhom kura dwar.

369
00:15:25,035 --> 00:15:27,830
U meta jien lest biex jiffrankaw din,
jekk l-internet tikkoopera,

370
00:15:27,830 --> 00:15:35,032
I ikklikkja Save, u ħafna, ħafna, ħafna
bil-mod ma 'l-database nikseb ffrankati.

371
00:15:35,032 --> 00:15:37,240
U issa jien lura għal dan
interface, li ċertament,

372
00:15:37,240 --> 00:15:38,680
huwa enormi fl-ewwel daqqa t'għajn.

373
00:15:38,680 --> 00:15:42,450
Imma kollha jien ser tagħmel hu li ikklikkja
fuq l-utenti verbali in quċċata xellug.

374
00:15:42,450 --> 00:15:47,630
Jien ser jitla 'hawn, ikklikkja
Utenti, u fil-kontumaċja, huwa

375
00:15:47,630 --> 00:15:50,180
tkun wettqet xi SQL, iżda
aktar fuq li fil-mument.

376
00:15:50,180 --> 00:15:52,654
Hawn biss sommarju ta 'dak li għamilt.

377
00:15:52,654 --> 00:15:55,320
U ma joqogħdu jinkwetaw li inti tara
isemmu ta Latin u Svediża hawn.

378
00:15:55,320 --> 00:16:00,490
Dawk huma biss l-default
settings, minħabba MySQL oriġinarjament,

379
00:16:00,490 --> 00:16:04,000
jew PHP MyAdmin, wieħed miż-żewġ ġara
li tkun miktuba minn xi persuni Svediż.

380
00:16:04,000 --> 00:16:06,100
Imma hija irrilevanti fil-każ tagħna hawn.

381
00:16:06,100 --> 00:16:08,280
>> Kull dritt, hekk għaliex huwa
dan kollu interessanti?

382
00:16:08,280 --> 00:16:13,050
Jirriżulta, I tista 'daħħal data
fi database billi tikteb kodiċi.

383
00:16:13,050 --> 00:16:15,940
U jien jimxi 'l quddiem u
fil-fajl tiegħi hawn, jien

384
00:16:15,940 --> 00:16:19,000
se jimxi 'l quddiem u nippretendu simili
dan huwa fili għall dik id-database, li

385
00:16:19,000 --> 00:16:23,040
mhuwiex fil-mument, iżda se
jkun meta nikbru għall-problema stabbiliti sebgħa.

386
00:16:23,040 --> 00:16:25,640
U jien ser jimxi 'l quddiem u
tesegwixxi funzjoni msejħa mistoqsija,

387
00:16:25,640 --> 00:16:28,730
li naghtuk fil-problema
sett seba s kodiċi distribuzzjoni, li

388
00:16:28,730 --> 00:16:31,490
jieħu argument l-anqas waħda,
li huwa biss sekwenza.

389
00:16:31,490 --> 00:16:33,460
A sensiela ta 'kodiċi SQL.

390
00:16:33,460 --> 00:16:36,700
Allura, int ser jitgħallmu kif
jiktbu Strutturat Mistoqsija Lingwa.

391
00:16:36,700 --> 00:16:41,270
>> Jekk irrid li tiddaħħal ringiela ġdida fis tiegħi
database minħabba xi ħadd ikun issottometta

392
00:16:41,270 --> 00:16:47,600
formola għall-kodiċi tiegħi, nixtieq litteralment
jiktbu DAĦĦAL FIS-utenti li ġej

393
00:16:47,600 --> 00:16:52,800
oqsma: username,
comma, isem, l-VALURI,

394
00:16:52,800 --> 00:16:57,480
u issa għandi bżonn biex tiddaħħal
xi ħaġa bħall Malan, u kwotazzjoni,

395
00:16:57,480 --> 00:17:01,490
"David Malan." unquote U issa
anki għal dawk familjari ma 'SQL,

396
00:17:01,490 --> 00:17:07,830
għaliex jien jużaw kwotazzjonijiet uniku
ġewwa ta 'din is-sekwenza aħdar?

397
00:17:07,830 --> 00:17:10,790

398
00:17:10,790 --> 00:17:13,040
Liema jista 'jkun ir-raġuni hawn?

399
00:17:13,040 --> 00:17:14,609
>> Avviż Jien ko-mingling żewġ lingwi.

400
00:17:14,609 --> 00:17:18,099
Mistoqsija hija funzjoni PHP,
iżda tieħu argument.

401
00:17:18,099 --> 00:17:21,740
U dan l-argument għandu innifsu jkun
miktub f'lingwa oħra msejħa

402
00:17:21,740 --> 00:17:23,500
SQL, Strutturat Mistoqsija Lingwa.

403
00:17:23,500 --> 00:17:27,940
Allura, dak kollu li I
għadek enfasizzat hawn

404
00:17:27,940 --> 00:17:30,380
hija din il-lingwa imsejħa SQL.

405
00:17:30,380 --> 00:17:36,290
Allura, x'hemm mal-kwotazzjonijiet uniku,
biss bħala kontroll sanità malajr?

406
00:17:36,290 --> 00:17:37,324
Jimxi 'l quddiem.

407
00:17:37,324 --> 00:17:37,990
Huma qed kordi.

408
00:17:37,990 --> 00:17:41,590
Allura, kwotazzjoni, Malan unquote u kwotazzjoni,
unquote David Malan huma kordi.

409
00:17:41,590 --> 00:17:45,210
U biss ħsieb intuwittivament issa,
jafu dak li taf dwar C u PHP,

410
00:17:45,210 --> 00:17:50,220
għaliex ma I ma tagħmel dan, li normalment I
kwotazzjonijiet doppja użati għall-kordi?

411
00:17:50,220 --> 00:17:52,310
Għaliex ma I ma trid tagħmel dan?

412
00:17:52,310 --> 00:17:52,810
Yeah?

413
00:17:52,810 --> 00:17:53,685
>> UDJENZA: [inaudible]

414
00:17:53,685 --> 00:17:56,695

415
00:17:56,695 --> 00:17:57,570
DAVID Malan: Eżattament.

416
00:17:57,570 --> 00:17:59,653
Għaliex jien diġà jużaw
kwotazzjonijiet doppja fuq il-mod

417
00:17:59,653 --> 00:18:01,929
barra tal-argument
għall-funzjoni PHP,

418
00:18:01,929 --> 00:18:03,470
Nixtieq biss jikkonfondi l-interpretu.

419
00:18:03,470 --> 00:18:04,860
Dan mhux se tkun taf, ma dawn imorru flimkien?

420
00:18:04,860 --> 00:18:05,735
Do dawn imorru flimkien?

421
00:18:05,735 --> 00:18:06,810
Do dawn imorru flimkien?

422
00:18:06,810 --> 00:18:08,070
So, I talterna minflok.

423
00:18:08,070 --> 00:18:11,784
>> Jew I jistgħu jagħmlu xi ħaġa bħal din,
kwotazzjoni backslash jew kwotazzjoni backslash.

424
00:18:11,784 --> 00:18:14,200
Franchement, li biss jibda
jiksbu ħafna ma jistgħux jinqraw u ikrah.

425
00:18:14,200 --> 00:18:16,790
Iżda dan kieku jinkiseb
l-istess riżultat ukoll.

426
00:18:16,790 --> 00:18:19,760
>> Għalhekk, jekk I kellhom tesegwixxi dan
query issa, ejja ara dak li jiġri.

427
00:18:19,760 --> 00:18:22,740
Jien ser jimxi 'l quddiem issa u aktar
minn tesegwixxi l-kodiċi PHP, li

428
00:18:22,740 --> 00:18:24,610
huwa fejn inti ser tilgħab
fl problema sett sebgħa,

429
00:18:24,610 --> 00:18:27,200
Jien ser minflok tmur għall MyAdmin PHP.

430
00:18:27,200 --> 00:18:29,770
U jien ser manwalment
biex tmur fil-tab SQL,

431
00:18:29,770 --> 00:18:31,580
u let me zoom fl fuq l-interface.

432
00:18:31,580 --> 00:18:34,007
U jien ser paste fil
il-ħaġa I biss ittajpjat.

433
00:18:34,007 --> 00:18:36,090
U l-kodifikazzjoni kulur għandu
nbidlu ftit issa,

434
00:18:36,090 --> 00:18:38,750
biss minħabba l-formati tal-programm
affarijiet ftit differenti.

435
00:18:38,750 --> 00:18:41,960
Iżda avviż li kollha I ghamilt
huwa Stajt qal, daħħal fis Utenti.

436
00:18:41,960 --> 00:18:45,790
Stajt speċifikat, imbagħad, fil virgola
lista parenthesized separati ż-żewġ

437
00:18:45,790 --> 00:18:48,850
oqsma li nixtieq li daħħal, u
imbagħad stajt litteralment qal valuri

438
00:18:48,850 --> 00:18:51,510
segwit minn paren ieħor,
U allura l-żewġ valuri

439
00:18:51,510 --> 00:18:53,520
Irrid li plug-in, u
issa għal miżura tajba,

440
00:18:53,520 --> 00:18:55,010
I ser jitqiegħdu b'semicolon fl-aħħar.

441
00:18:55,010 --> 00:18:56,570
Allura, dan mhux C. Dan mhux PHP.

442
00:18:56,570 --> 00:18:59,970
Dan issa huwa SQL, u jien pasta
fis din il-web interface bbażati thats

443
00:18:59,970 --> 00:19:02,710
biss ser let me,
malli I ikklikkja Go,

444
00:19:02,710 --> 00:19:08,060
teżegwixxi din il-mistoqsija dwar id-database
tmexxija ġewwa tal IDE CS50.

445
00:19:08,060 --> 00:19:09,470
>> Allura dan huwa tajjeb.

446
00:19:09,470 --> 00:19:12,520
Avviż li qal ringiela waħda
jiddaħħal, marru super fast,

447
00:19:12,520 --> 00:19:15,190
0.0054 sekondi biex jiddaħħal li data.

448
00:19:15,190 --> 00:19:16,610
Allura, li l-ħsejjes pretty b'saħħithom.

449
00:19:16,610 --> 00:19:19,350
Hija ifformattja mistoqsija tiegħi
għalija hawn biss biex tara li

450
00:19:19,350 --> 00:19:21,730
fil-tip ta 'kulur kodifikati verżjoni.

451
00:19:21,730 --> 00:19:24,540
Imma issa jekk I ikklikkja
Browse, avviż li, anki

452
00:19:24,540 --> 00:19:29,070
għalkemm hemm ħafna ta 'imbarazz fuq
l-iskrin, il-mejda tiegħi issa għandha żewġ ringieli.

453
00:19:29,070 --> 00:19:30,700
>> Allura, let me imorru quddiem u jagħmlu ieħor.

454
00:19:30,700 --> 00:19:33,760
Minflok dan, let me
mur l-tab SQL darb'oħra.

455
00:19:33,760 --> 00:19:40,723
U din id-darba jien ser daħħal xi ħaġa simili
Rob u ismu se jkun Rob Bowden.

456
00:19:40,723 --> 00:19:42,330
Bowden.

457
00:19:42,330 --> 00:19:44,040
Ejja ikklikkja Save.

458
00:19:44,040 --> 00:19:46,140
Oops, pjuttost Go.

459
00:19:46,140 --> 00:19:48,890
>> Ikklikkja Browse darb'oħra, u
issa Avviż Għandi żewġ ringieli.

460
00:19:48,890 --> 00:19:52,390
Allura, dan huwa biss kumpless b'mod aktar
mod ta 'ftuħ Google ispreadsheets

461
00:19:52,390 --> 00:19:54,010
u biss ittajpjar filliera fi kolonna.

462
00:19:54,010 --> 00:19:57,070
Imma x'hemm importanti hu li
issa għandna l-sintassi

463
00:19:57,070 --> 00:20:00,220
li biex jikteb il-kodiċi sabiex
finalment, nistgħu attwalment

464
00:20:00,220 --> 00:20:01,790
jagħmlu xi u dan.

465
00:20:01,790 --> 00:20:05,380
Ifakkar li jappoġġja PHP
varjabbli super globali.

466
00:20:05,380 --> 00:20:08,415
>> Dak li hu ġewwa ta 'dollaru
sinjal jenfasizzaw IKOLLOK fil-PHP?

467
00:20:08,415 --> 00:20:10,290
Aħna ħa ħarsa lejn wieħed
jew żewġ eżempji sempliċi.

468
00:20:10,290 --> 00:20:15,640
U fl PSet6, recall għandek bonjour
dot PHP li juża din il-varjabbli.

469
00:20:15,640 --> 00:20:17,870
X'inhu jiġri fil hemmhekk?

470
00:20:17,870 --> 00:20:21,015
Jew x'inhu?

471
00:20:21,015 --> 00:20:22,522
A louder ftit.

472
00:20:22,522 --> 00:20:23,790
>> UDJENZA: [inaudible]

473
00:20:23,790 --> 00:20:25,030
>> DAVID Malan: Huwa borra
żerriegħa tal array, li

474
00:20:25,030 --> 00:20:27,714
huwa biss mod fancy ta 'tgħid xi
firxa li għandha pari b'valur ewlenin.

475
00:20:27,714 --> 00:20:28,880
U ċ-ċwievet mhumiex numerika.

476
00:20:28,880 --> 00:20:30,420
Huma qed kliem jew kordi.

477
00:20:30,420 --> 00:20:32,750
U speċifikament, liema
huma dawk pari b'valur ewlenin?

478
00:20:32,750 --> 00:20:35,110
Fejn huma ġejjin minn?

479
00:20:35,110 --> 00:20:35,620
Jiddispjacini?

480
00:20:35,620 --> 00:20:36,994
>> UDJENZA: [inaudible]

481
00:20:36,994 --> 00:20:37,660
DAVID Malan: Nru?

482
00:20:37,660 --> 00:20:40,700
Fejn do dawk ewlenin
pari b'valur jiġu minn?

483
00:20:40,700 --> 00:20:42,490
Say mill-ġdid?

484
00:20:42,490 --> 00:20:44,610
Għal darb'oħra?

485
00:20:44,610 --> 00:20:46,472
Am I-unika ħaġa f'seduta waħda?

486
00:20:46,472 --> 00:20:47,810
>> [Rires]

487
00:20:47,810 --> 00:20:49,042
>> Dak id-dritt, iva?

488
00:20:49,042 --> 00:20:50,435
>> UDJENZA: [inaudible]

489
00:20:50,435 --> 00:20:52,560
DAVID Malan: Yeah, huma
ġejjin mill-sekwenza mistoqsija.

490
00:20:52,560 --> 00:20:55,380
Għalhekk, jekk inti kontrina fil-ħin biex
meta konna lagħbu Google

491
00:20:55,380 --> 00:20:59,600
u konna marret għal mmejla Google.com
tfittxija trade mark in kwistjoni q ugwali qtates,

492
00:20:59,600 --> 00:21:03,550
jekk I kellhom hit Ikteb u jekk
Google ġew implimentati fil-PHP,

493
00:21:03,550 --> 00:21:07,017
Kodiċi PHP li Google kiteb
jkollhom aċċess għal sinjal dollaru

494
00:21:07,017 --> 00:21:11,600
jenfasizzaw tikseb ġewwa minnhom
hija essenzjali tissejjaħ Q u valur

495
00:21:11,600 --> 00:21:17,680
imsejħa qtates li jistgħu mbagħad jużaw
użati biex jagħmlu tfittxija attwali mal.

496
00:21:17,680 --> 00:21:20,860
>> Allura, fil-fatt, dak li jien ser
tagħmel issa hu li jmur lura għall-kodiċi PHP tiegħi

497
00:21:20,860 --> 00:21:23,140
li inti ser terġa tara aktar ta 'fil PSet7.

498
00:21:23,140 --> 00:21:25,440
U minflok ta 'fejn jitwaħħal
fil-valuri kodifikati iebes li

499
00:21:25,440 --> 00:21:27,630
ma jidhru simili
ħafna website dinamiku,

500
00:21:27,630 --> 00:21:30,680
Jien ser jagħtuk teaser ta
liema kodiċi attwali tiegħek ser jagħmlu.

501
00:21:30,680 --> 00:21:32,854
Inti tpoġġi f'żewġ
kwistjoni marki bħal dan.

502
00:21:32,854 --> 00:21:34,270
I do not know dak l-username hu.

503
00:21:34,270 --> 00:21:37,390
I do not know dak l-
isem se tkun,

504
00:21:37,390 --> 00:21:39,470
imma I do know I tista '
tikseb minnhom dinamiku.

505
00:21:39,470 --> 00:21:43,420
>> Għalhekk, jekk il-kodiċi aħna qed miktub issa huwa
il-kodiċi taħdem fuq servers Google,

506
00:21:43,420 --> 00:21:46,940
jew jekk dan huwa bonjour dot
PHP, li tiġi ma PSet6,

507
00:21:46,940 --> 00:21:48,650
Jien ser jgħaddu fil
il-funzjoni mistoqsija

508
00:21:48,650 --> 00:21:51,450
bħad printf, żewġ argumenti oħra.

509
00:21:51,450 --> 00:21:57,120
IKOLLOK, kwotazzjoni, username unquote,
u IKOLLOK, kwotazzjoni, l-isem unquote.

510
00:21:57,120 --> 00:22:00,720
U issa, avviż dak il
istruttura ġenerali huwa hawnhekk.

511
00:22:00,720 --> 00:22:03,320
Stajt qbilna fuq ix-xellug
naħa tas-sejħa,

512
00:22:03,320 --> 00:22:05,480
din il-funzjoni tissejjaħ mistoqsija fil-PHP.

513
00:22:05,480 --> 00:22:08,160
I għad għandhom bħala l-ewwel
argument, biss sensiela ta 'test.

514
00:22:08,160 --> 00:22:11,000
>> Iżda dan sekwenza tat-test huwa
miktub fl-lingwa imsejjaħ SQL.

515
00:22:11,000 --> 00:22:12,616
U franchement, mhuwiex lingwa big.

516
00:22:12,616 --> 00:22:14,990
Aħna biss ser jitkellmu dwar
formalment illum, tassew.

517
00:22:14,990 --> 00:22:17,031
U mbagħad fl problema stabbiliti
seba ', hemm relattivament

518
00:22:17,031 --> 00:22:18,800
ftit karatteristiċi li aħna qed
se lieva.

519
00:22:18,800 --> 00:22:22,530
Il trade marks in kwistjoni, għalkemm, tfisser plagg fil
valur hawn u plug fil-valur ieħor

520
00:22:22,530 --> 00:22:23,130
hawn.

521
00:22:23,130 --> 00:22:26,010
U avviż, stajt naqset dak
minn madwar id-kkritikat quote--

522
00:22:26,010 --> 00:22:30,470
it-- madwar il-kwotazzjoni
jimmarka din id-darba.

523
00:22:30,470 --> 00:22:34,930
Stajt titħalla barra l-kwotazzjoni
marki madwar id-trade mark in kwistjoni,

524
00:22:34,930 --> 00:22:36,410
sorry, din id-darba.

525
00:22:36,410 --> 00:22:38,870
>> Allura, x'hemm sbieħ dwar dan
marka kwistjoni karatteristika li

526
00:22:38,870 --> 00:22:42,830
PHP tendenza li jappoġġjaw, Ruby u
Python u lingwi oħra,

527
00:22:42,830 --> 00:22:45,730
dan ifisser biss plug f'xi
valur hawn u inti taf liema?

528
00:22:45,730 --> 00:22:48,300
Inti figura jekk l-użu
kwotazzjonijiet uniku jew kwotazzjonijiet doppja.

529
00:22:48,300 --> 00:22:50,966
Ma jolqot lili ma 'dawk
Dettalji intellettwalment uninteresting.

530
00:22:50,966 --> 00:22:53,780
Iżda, kun ċert li huwa korrett
sabiex kodiċi tiegħi huwa finalment

531
00:22:53,780 --> 00:22:57,010
operattiv u sigur, li
se jkollu tifsira qabel fit-tul.

532
00:22:57,010 --> 00:23:00,460
>> Issa, kemm argumenti totali, just biex
ikunu ċari, huwa t-teħid funzjoni query?

533
00:23:00,460 --> 00:23:05,240

534
00:23:05,240 --> 00:23:07,581
Kull min jixtiequ li jivvutaw għal aktar minn tnejn?

535
00:23:07,581 --> 00:23:08,080
Tliet?

536
00:23:08,080 --> 00:23:10,001
Sure, għaliex?

537
00:23:10,001 --> 00:23:10,920
Għaliex tliet?

538
00:23:10,920 --> 00:23:12,305
>> UDJENZA: [inaudible]

539
00:23:12,305 --> 00:23:13,180
DAVID Malan: Eżattament.

540
00:23:13,180 --> 00:23:14,610
L-ewwel parti hija l-sekwenza.

541
00:23:14,610 --> 00:23:18,640
It-tieni argument huwa sinjal dollaru
jenfasizzaw IKOLLOK username parentesi.

542
00:23:18,640 --> 00:23:21,950
U t-tielet argument huwa l-
istess ħaġa, iżda biss l-isem.

543
00:23:21,950 --> 00:23:24,590
Allura fi kliem ieħor, issa
jekk I kellhom formola tal-web

544
00:23:24,590 --> 00:23:27,149
li kellhom oqsma test,
waħda għall username-utent,

545
00:23:27,149 --> 00:23:29,690
wieħed għal tiegħu jew l-isem tagħha, just
bħal inti tara fil-website

546
00:23:29,690 --> 00:23:32,120
meta inti tirreġistra għal
xi websajt, dan jista '

547
00:23:32,120 --> 00:23:35,450
jkun il-kodiċi fuq il-aħħar lura li
attwalment ma l-inserzjoni issa

548
00:23:35,450 --> 00:23:37,220
fid-database.

549
00:23:37,220 --> 00:23:40,870
>> Issa għall-kuntrarju, ejja fast quddiem.

550
00:23:40,870 --> 00:23:43,840
Ejja ngħidu utent issa huwa
qtugħ fi u inti tixtieq

551
00:23:43,840 --> 00:23:48,860
li jikteb il-kodiċi PHP li l-kontrolli jekk
il-persuna li jinsab biss illoggjat

552
00:23:48,860 --> 00:23:52,250
huwa attwalment utent, inti tista '
jużaw sintassi pretty sempliċi.

553
00:23:52,250 --> 00:23:55,832
Tista 'tgħid TAGĦŻEL, ejja ngħidu
star, fejn star tfisser dak kollu.

554
00:23:55,832 --> 00:23:57,540
I do not know dak I
trid, hekk biss jagħtu me

555
00:23:57,540 --> 00:24:01,585
l-kolonni mit-tabella
imsejħa utenti meta, u dan huwa sbieħ.

556
00:24:01,585 --> 00:24:03,710
Agħżel jappoġġja x'hemm
imsejħa relattivi, li hija

557
00:24:03,710 --> 00:24:06,630
bħal mod ta 'kwalifikazzjoni dak li trid.

558
00:24:06,630 --> 00:24:10,590
Fejn username ugwali
kwotazzjoni, unquote Malan.

559
00:24:10,590 --> 00:24:13,680
Allura hawnhekk ukoll, stajt inkorporati
ġewwa l-argument

560
00:24:13,680 --> 00:24:16,110
għal funzjoni PHP, linja ta 'kodiċi SQL.

561
00:24:16,110 --> 00:24:18,680
U dak il-kodiċi SQL dan
ħin huwa litteralment tmur

562
00:24:18,680 --> 00:24:21,790
ta 'tiftix għal kwotazzjoni, unquote Malan.

563
00:24:21,790 --> 00:24:24,420
>> Issa dak li mhux kollha li utli,
hekk jien ser skip li

564
00:24:24,420 --> 00:24:28,650
u jien ser poġġejt
dan il-ponta minn Brady, u jmorru

565
00:24:28,650 --> 00:24:30,990
u plug-in minflok
kwistjoni mark hawn.

566
00:24:30,990 --> 00:24:33,290
Għalhekk, biss li jkun ċar, liema
għandhom jissekondaw argument tiegħi

567
00:24:33,290 --> 00:24:37,480
jiġu jekk xi ħadd għadu kif illoggjat u I
jridu jiċċekkjaw jekk hu jew hi attwalment

568
00:24:37,480 --> 00:24:39,265
utent?

569
00:24:39,265 --> 00:24:40,140
UDJENZA: [inaudible]

570
00:24:40,140 --> 00:24:40,890
DAVID Malan: Yeah.

571
00:24:40,890 --> 00:24:44,120
Nisma dollaru jenfasizzaw sinjal
IKOLLOK kwotazzjoni, username unquote.

572
00:24:44,120 --> 00:24:50,040
U li għandhom jirritornaw lill me
kwalunkwe mill-ringieli fid-database tiegħi

573
00:24:50,040 --> 00:24:51,986
li jkollhom username ta Malan.

574
00:24:51,986 --> 00:24:54,860
Issa nisperaw, jien ser terġa 'lura
żero jekk l Malan qatt kien hawn,

575
00:24:54,860 --> 00:24:56,290
jew wieħed jekk ikollu.

576
00:24:56,290 --> 00:24:59,026
I ma għandhom jingħataw lura
tnejn jew tlieta jew erba '.

577
00:24:59,026 --> 00:24:59,526
Għaliex?

578
00:24:59,526 --> 00:25:00,220
>> UDJENZA: [inaudible]

579
00:25:00,220 --> 00:25:01,120
>> DAVID Malan: I said uniku, id-dritt?

580
00:25:01,120 --> 00:25:01,750
Sempliċi raġuni.

581
00:25:01,750 --> 00:25:04,030
Minħabba I qal li ltqajna biex
tkun unika, biss loġikament,

582
00:25:04,030 --> 00:25:07,940
inti tista 'biss ikollha żero jew wieħed Malans
f'din it-tabella database partikolari.

583
00:25:07,940 --> 00:25:10,965
Issa bħala twarrib, biss sabiex inti stajt tidher
dan, anki jekk I iżommu jużaw IKOLLOK

584
00:25:10,965 --> 00:25:14,350
u anki jekk PSet6 jintuża biss
IKOLLOK, inti tista 'ċertament POST.

585
00:25:14,350 --> 00:25:17,212
U tfakkar li hija ieħor Post
teknika għall-preżentazzjoni ta 'informazzjoni

586
00:25:17,212 --> 00:25:19,170
minn forma, iżda
ma juru up fil-URL.

587
00:25:19,170 --> 00:25:22,690
Huwa ftit aktar sigur ċertament għal
affarijiet simili usernames u passwords,

588
00:25:22,690 --> 00:25:25,210
li PSet7 se, fil-fatt, jinvolvu.

589
00:25:25,210 --> 00:25:28,130
>> Allura, ejja tagħmel dan fil-PHP
MyAdmin u tara x'jiġri.

590
00:25:28,130 --> 00:25:30,020
Jien se jmorru biex tab MySQL.

591
00:25:30,020 --> 00:25:34,450
U tinnota li l-valur awtomatiku għall
PHP MyAdmin, just biex jipprova jkun utli,

592
00:25:34,450 --> 00:25:37,050
huwa li tagħżel star minn utenti fejn ikunu.

593
00:25:37,050 --> 00:25:39,430
Ukoll, wieħed huwa dejjem veru, hekk
dan għandu l-iblah effettiv

594
00:25:39,430 --> 00:25:40,400
ta 'ftit tagħżel kollox.

595
00:25:40,400 --> 00:25:42,691
Imma jien ser tkun ftit
aktar pedantic u manwalment

596
00:25:42,691 --> 00:25:45,920
tip out star jintgħażlu minn utenti.

597
00:25:45,920 --> 00:25:48,294
>> Issa teknikament, inti tista '
nikkwota l-isem tat-tabelli.

598
00:25:48,294 --> 00:25:50,460
Huwa rari li inti għandek,
iżda tinnota dawn mhumiex

599
00:25:50,460 --> 00:25:52,240
kwotazzjonijiet normali tiegħek fuq it-tastiera Istati Uniti.

600
00:25:52,240 --> 00:25:54,760
Dan huwa l-hekk imsejħa backtick, li
hija ġeneralment fuq il-naħa tax-xellug

601
00:25:54,760 --> 00:25:56,000
kantuniera ta 'tastiera tiegħek.

602
00:25:56,000 --> 00:25:58,500
Iżda huwa rari li tkun taf
fil-fatt bżonn li jolqot ma 'dan,

603
00:25:58,500 --> 00:25:59,950
so I taf biss jħalli barra minnhom xorta waħda.

604
00:25:59,950 --> 00:26:02,280
Allura issa, let me imorru quddiem u hit tmur.

605
00:26:02,280 --> 00:26:06,616
U kemm ringieli għandi nikseb
lura meta I jagħżlu star minn utenti?

606
00:26:06,616 --> 00:26:08,407
>> UDJENZA: [inaudible]

607
00:26:08,407 --> 00:26:09,990
DAVID Malan: In-numru ta 'ringieli, żgur.

608
00:26:09,990 --> 00:26:12,390
Imma kemm f'dan
istorja konkreti dritt issa?

609
00:26:12,390 --> 00:26:14,640
Tnejn, minħabba li kien hemm
lili u kien hemm Rob.

610
00:26:14,640 --> 00:26:19,370
Għalhekk, jekk I ikklikkja Go, nara viżwalment li
Stajt gotten lura, tabilħaqq, żewġ ringieli.

611
00:26:19,370 --> 00:26:22,060
Hemm ħafna ta 'imbarazz fuq il-
screen, imma jien biss tara żewġ ringieli.

612
00:26:22,060 --> 00:26:28,580
B'kuntrast, jekk nagħmel dan mill-ġdid u tagħmel
Star TAGĦŻEL MINN utenti, fejn username

613
00:26:28,580 --> 00:26:31,840
ugwali kwotazzjoni, unquote
Malan, issa jekk I ikklikkja Go,

614
00:26:31,840 --> 00:26:33,970
Jien biss se terġa 'lura ringiela waħda.

615
00:26:33,970 --> 00:26:36,499
U fl-aħħar, jekk I do
xi ħaġa bħal din, ejja ngħidu

616
00:26:36,499 --> 00:26:38,290
li jien ma care about
jkollna kollox,

617
00:26:38,290 --> 00:26:41,020
li huwa tip ta 'bla sens issa,
għaliex hemm biss żewġ kolonni.

618
00:26:41,020 --> 00:26:43,103
Mhuwiex simili jien għażla
ammont kbir ta 'data.

619
00:26:43,103 --> 00:26:46,720
Ejja ngħidu I jimxi 'l quddiem u
do TAGĦŻEL isem MILL

620
00:26:46,720 --> 00:26:51,990
utenti, fejn username jiġi daqs Malan,
x'hemm sbieħ dwar SQL onestament,

621
00:26:51,990 --> 00:26:54,290
hija li verament ftit ma
dak li inti tgħid li tagħmel.

622
00:26:54,290 --> 00:26:57,550
Huwa pretty konċiża, iżda inti litteralment
biss għid dak li inti trid tagħmel.

623
00:26:57,550 --> 00:27:01,130
Isem Agħżel minn utenti fejn ikun
il username ugwali Malan.

624
00:27:01,130 --> 00:27:03,440
U huwa verament huwa li espliċita.

625
00:27:03,440 --> 00:27:08,410
Allura, issa jekk I hit Go, kemm
ringieli am I se terġa 'lura?

626
00:27:08,410 --> 00:27:10,770
Waħda, għaliex huwa biss Malan, nisperaw.

627
00:27:10,770 --> 00:27:13,100
Jew zero jekk huwa ma
hemm, iżda wieħed maximally.

628
00:27:13,100 --> 00:27:17,610
>> U kemm kolonni se niġi lura?

629
00:27:17,610 --> 00:27:18,450
Kif kolonni ħafna?

630
00:27:18,450 --> 00:27:20,658
Din id-darba, jien biss ser
li tikseb wieħed minħabba I ma

631
00:27:20,658 --> 00:27:22,380
tagħżel stilla, li huwa kollox.

632
00:27:22,380 --> 00:27:27,900
Issa jien għażla biss isem, so I
biss jiksbu lura kolonna waħda u ringiela waħda.

633
00:27:27,900 --> 00:27:31,730
U jidher tip ta 'xieraq
redikoli, biss tħares super

634
00:27:31,730 --> 00:27:33,060
żgħar bħal dan.

635
00:27:33,060 --> 00:27:34,290
Allura, dak li verament jiġri?

636
00:27:34,290 --> 00:27:36,890
Meta inti teżegwixxi SQL
query użu tagħżel,

637
00:27:36,890 --> 00:27:38,700
dak li qed jkollna
lura mid-database

638
00:27:38,700 --> 00:27:42,970
huwa bħal tabella temporanju
ma ringieli u kolonni, forsi,

639
00:27:42,970 --> 00:27:46,260
iżda li jħalli barra xejn li
ma kienux attwalment magħżula minnek.

640
00:27:46,260 --> 00:27:49,010
Allura, huwa simili jekk xi ħadd kellu big
spreadsheet mill-istudenti kollha

641
00:27:49,010 --> 00:27:51,610
irreġistrata għal xi
grupp student, u inti tgħidli,

642
00:27:51,610 --> 00:27:55,097
jagħtu me kollha tal-freshman li ħadthom
irreġistrata għall-grupp student tagħna, dak

643
00:27:55,097 --> 00:27:56,930
kollega tiegħek fil-
grupp student tista 'tagħmel

644
00:27:56,930 --> 00:27:58,430
huwa dawn jistgħu sempliċement naħa
inti l-spreadsheet kollu.

645
00:27:58,430 --> 00:27:59,742
C'est simili qal star tagħżel.

646
00:27:59,742 --> 00:28:02,200
U huwa ftit annoying jekk
inti biss riedu l freshman.

647
00:28:02,200 --> 00:28:05,640
U hekk, jekk inti minflok qal,
star tagħżel minn tabella database

648
00:28:05,640 --> 00:28:08,470
fejn sena ugwali
kwotazzjoni, freshman unquote,

649
00:28:08,470 --> 00:28:10,810
huwa bħallikieku ħabib tiegħek
fil-grupp istudent

650
00:28:10,810 --> 00:28:13,770
litteralment enfasizzat u
kkupjati biss il-fillieri Freshman,

651
00:28:13,770 --> 00:28:16,780
pasted tagħhom fiċ-Google ġdida
Spreadsheet jew fajl Excel,

652
00:28:16,780 --> 00:28:18,860
u mogħtija inti lura l-
fajl jirriżulta biss.

653
00:28:18,860 --> 00:28:21,710
Li kollox li għaddej
fuq kunċettwalment hawn.

654
00:28:21,710 --> 00:28:23,920
>> Għalhekk fl-aħħar, nistgħu nagħmlu
xi affarijiet pretty fancy

655
00:28:23,920 --> 00:28:26,560
billi jaħżnu affarijiet simili usernames
u passwords u simili.

656
00:28:26,560 --> 00:28:30,310
Iżda, jirriżulta, għandna nagħmlu
ftit differenti minn dan.

657
00:28:30,310 --> 00:28:34,750
Dan m'huwiex smart biss
jaħżnu username u password.

658
00:28:34,750 --> 00:28:37,790
Xi ħadd qabel, naħseb
stabbiliti hawn, ssuġġeriet ID.

659
00:28:37,790 --> 00:28:40,787
Issa ID tista 'tkun bħal
Harvard ID jew ID Net Yale, il

660
00:28:40,787 --> 00:28:42,870
iżda tista 'tkun saħansitra aktar sempliċi
fil-każ database tagħna.

661
00:28:42,870 --> 00:28:45,120
U fil-fatt, il-każ komuni
huwa li jkun kolonna ieħor.

662
00:28:45,120 --> 00:28:46,953
U jien se jmorru
quddiem u jeditjaw mejda tiegħi.

663
00:28:46,953 --> 00:28:49,521
U jekk inti play madwar
dan interface għall PSet7,

664
00:28:49,521 --> 00:28:51,770
tkun taf tara li inti tista 'tivverifika
din il-buttuna hawn u żid

665
00:28:51,770 --> 00:28:53,750
qasam fil-bidu tat-tabella.

666
00:28:53,750 --> 00:28:56,720
U issa jekk I ikklikkja Go, li għaddej
li tagħti me wieħed minn dawk forom

667
00:28:56,720 --> 00:28:57,600
minn qabel.

668
00:28:57,600 --> 00:29:00,170
Jien ser iżid qasam imsejjaħ ID.

669
00:29:00,170 --> 00:29:03,070
U jien ser jagħmilha tip numerika.

670
00:29:03,070 --> 00:29:05,362
>> I jkollhom mazz sħiħ
ta 'valuri għal numerics.

671
00:29:05,362 --> 00:29:08,677
Jien biss ser jagħżlu INT u
Ma joqogħdu jinkwetaw dwar l-daqsijiet differenti.

672
00:29:08,677 --> 00:29:10,510
I ma jkollhom jispeċifika
tul jew valur,

673
00:29:10,510 --> 00:29:13,710
minħabba li għaddej biex tkun
32 bits x'ikun.

674
00:29:13,710 --> 00:29:16,070
Attributi, aħna ma tara qabel.

675
00:29:16,070 --> 00:29:18,410
Xi interess fi kwalunkwe minn dawn
għażliet menu din id-darba?

676
00:29:18,410 --> 00:29:21,890

677
00:29:21,890 --> 00:29:23,745
Għal INT?

678
00:29:23,745 --> 00:29:24,620
What did you tipproponi?

679
00:29:24,620 --> 00:29:27,350

680
00:29:27,350 --> 00:29:28,445
Nru?

681
00:29:28,445 --> 00:29:29,570
Do xi wieħed minn dawn jagħmlu sens?

682
00:29:29,570 --> 00:29:30,536
Yeah.

683
00:29:30,536 --> 00:29:31,900
Yeah, mhux iffirmat, id-dritt?

684
00:29:31,900 --> 00:29:35,930
>> Ġeneralment, jekk aħna qed tmur biex jagħtu
kulħadd numru uniku, li

685
00:29:35,930 --> 00:29:38,200
huwa fejn din l-istorja hija
tmur, I verament irridu biss

686
00:29:38,200 --> 00:29:41,919
persuna li jkollha n-numru simili żero
u wieħed u tnejn u tlieta u erbgħa.

687
00:29:41,919 --> 00:29:43,710
I m'għandhomx bżonn li jittrattaw
bin-numri negattivi.

688
00:29:43,710 --> 00:29:45,210
Hija biss tidher bħal kumplessità bla bżonn.

689
00:29:45,210 --> 00:29:48,470
Irrid erba biljun valuri possibbli,
mhux erba 'biljun valuri possibbli,

690
00:29:48,470 --> 00:29:50,699
so I biss irdoppja l
kapaċità tal INT tiegħi.

691
00:29:50,699 --> 00:29:53,490
Bħala twarrib, jekk inti tixtieq li jirrelataw
dan għal xi ħaġa bħal Facebook,

692
00:29:53,490 --> 00:29:56,190
lura fil-tip ta 'ġurnata tiegħi meta
Facebook ewwel daħal out,

693
00:29:56,190 --> 00:29:59,510
Nemmen dak li kienu
użu fl MySQL database tagħhom

694
00:29:59,510 --> 00:30:02,856
biex jaħżnu s utent
identifikatur, kien biss ta 'INT.

695
00:30:02,856 --> 00:30:05,230
Iżda naturalment, hemm ħafna
ta 'persuni reali fid-dinja.

696
00:30:05,230 --> 00:30:07,438
Hemm ħafna ta 'foloz Facebook
kontijiet fid-dinja.

697
00:30:07,438 --> 00:30:11,701
U għalhekk eventwalment, Facebook fawrien
id-daqs ta 'INT, a erba' biljun

698
00:30:11,701 --> 00:30:12,200
valur.

699
00:30:12,200 --> 00:30:15,032
Liema hu għaliex, jekk inti tħares
madwar u hemm websajts

700
00:30:15,032 --> 00:30:16,740
li jista 'jgħidlek liema
ID unika tiegħek.

701
00:30:16,740 --> 00:30:19,781
U jekk int qatt għażlet username fi
Facebook, tkun taf tara ID unika tiegħek.

702
00:30:19,781 --> 00:30:23,080
Naħseb li huwa profil dot PHP
trade mark in kwistjoni ID ugwali xi ħaġa.

703
00:30:23,080 --> 00:30:27,210
Li issa huwa xi ħaġa bħal big
INT, jew twil twil jekk inti se,

704
00:30:27,210 --> 00:30:29,700
li hija valur 64-bit
jew xi ħaġa simili.

705
00:30:29,700 --> 00:30:33,620
>> Għalhekk, anki fid-dinja reali tagħmel dawn
kwistjonijiet finalment kultant jimpurtax.

706
00:30:33,620 --> 00:30:37,600
U jirriżulta li hawnhekk, jekk jien
tagħti kollha ta 'utenti tiegħi ID unika,

707
00:30:37,600 --> 00:30:41,750
Nixtieq inkun super espliċita u
minimament jagħmlu dan il-qasam uniku.

708
00:30:41,750 --> 00:30:44,750
Iżda jirriżulta hemm wieħed
biċċa nomenklatura illum wisq

709
00:30:44,750 --> 00:30:46,470
li l-kodiċi primarju.

710
00:30:46,470 --> 00:30:49,800
Jekk int tfassil ta 'database
mejda u inti taf minn qabel

711
00:30:49,800 --> 00:30:55,580
li waħda mill-kolonni dik it-tabella
għandhom u se jidentifika unikament ringieli

712
00:30:55,580 --> 00:30:58,500
fit-tabella, inti tixtieq li
jispeċifika dan u tell-database,

713
00:30:58,500 --> 00:31:00,250
dan huwa kodiċi primarju tiegħi.

714
00:31:00,250 --> 00:31:02,110
Jista 'jkun hemm duplikati
f'oqsma oħra,

715
00:31:02,110 --> 00:31:06,330
imma jien javżak-database li din
huwa primarja tiegħi, iktar settur importanti tiegħi,

716
00:31:06,330 --> 00:31:08,420
li garantit li jkun uniku.

717
00:31:08,420 --> 00:31:09,660
>> Issa, dan jidher superfluwu.

718
00:31:09,660 --> 00:31:13,830
I am issa tipproponi li aħna
żid, billi tikklikkja Save hawn,

719
00:31:13,830 --> 00:31:17,210
a called-- qasam u jien ser
li jimxi 'l quddiem u kklikkja AI,

720
00:31:17,210 --> 00:31:19,720
aħna ser terga 'lura għal
li fil-mument, Save.

721
00:31:19,720 --> 00:31:22,540
Qed nipproponi issa li
tabella tiegħi look like dan.

722
00:31:22,540 --> 00:31:26,305
I jkollhom kamp INT imsejħa ID,
qasam CHAR imsejjaħ Username,

723
00:31:26,305 --> 00:31:31,100
qasam varchar imsejjaħ Isem, iżda ID,
jekk huwa primarja u għalhekk uniku,

724
00:31:31,100 --> 00:31:33,760
għaliex ma I biss skart
ħin jiġi introdott dak

725
00:31:33,760 --> 00:31:39,140
effettivament hija t-tieni unika
qasam imsejħa ID thats INT?

726
00:31:39,140 --> 00:31:41,980
>> Username, irtirar, kien
diġà unika, għidna.

727
00:31:41,980 --> 00:31:45,350
Hekk biss loġikament, inti m'għandekx bżonn
kwalunkwe esperjenza database biex raġuni

728
00:31:45,350 --> 00:31:47,570
permezz ta 'dan, għaliex
jista I introduċew

729
00:31:47,570 --> 00:31:50,065
l INT kif identifikatur uniku tiegħi ukoll?

730
00:31:50,065 --> 00:31:52,740

731
00:31:52,740 --> 00:31:53,930
X'hemm this-- ngħid mill-ġdid?

732
00:31:53,930 --> 00:31:55,580
>> UDJENZA: [inaudible]

733
00:31:55,580 --> 00:31:59,534
>> DAVID Malan: Random
aċċess huwa aktar faċli, għaliex?

734
00:31:59,534 --> 00:32:00,410
>> UDJENZA: [inaudible]

735
00:32:00,410 --> 00:32:02,367
DAVID Malan: Yeah, huwa
biss aċċess numri.

736
00:32:02,367 --> 00:32:04,750
Għalhekk, jekk inti taħseb ta 'dan verament
huwa tabella, bħal firxa,

737
00:32:04,750 --> 00:32:07,690
issa għandi identifikaturi uniċi
li I tista 'tiżdied madwar.

738
00:32:07,690 --> 00:32:11,520
U aħjar minn dak xorta hija li
kemm hu kbir huwa l INT se tkun mill-ġdid?

739
00:32:11,520 --> 00:32:14,450

740
00:32:14,450 --> 00:32:15,800
32 bits jew erba 'bytes.

741
00:32:15,800 --> 00:32:17,750
>> Kemm hi kbira l username tiegħi se tkun?

742
00:32:17,750 --> 00:32:20,310

743
00:32:20,310 --> 00:32:21,990
Maximally?

744
00:32:21,990 --> 00:32:22,880
16 bytes.

745
00:32:22,880 --> 00:32:26,080
>> Allura, jekk int verament ħsieb dwar
il-prestazzjoni tal-kodiċi tiegħek,

746
00:32:26,080 --> 00:32:31,390
think lura għall PSet5, kieku inti tippreferi
ta 'tiftix għal valur erba byte jew 16

747
00:32:31,390 --> 00:32:32,240
valur byte, id-dritt?

748
00:32:32,240 --> 00:32:33,810
Huwa verament huwa sempliċi bħal dik.

749
00:32:33,810 --> 00:32:38,060
Inti għandek tagħmel erba 'darbiet aktar xogħol
ta 'tiftix għal usernames għaliex dawk

750
00:32:38,060 --> 00:32:38,830
huma 16 bytes.

751
00:32:38,830 --> 00:32:41,320
Allura, inti għandek litteralment
iqabblu 16 bytes kollha li jkunu

752
00:32:41,320 --> 00:32:43,140
żgur iva, dan huwa username irrid.

753
00:32:43,140 --> 00:32:46,610
Billi għal INT, inti tista
jagħmlu dan bil biss erba 'bytes.

754
00:32:46,610 --> 00:32:49,212
>> U bħala twarrib għal dawk
interessati fil-hardware tal-kompjuter,

755
00:32:49,212 --> 00:32:52,420
jirriżulta inti tista tajbin xi ħaġa bħal
l INT jew valur 32-bit fil xi ħaġa

756
00:32:52,420 --> 00:32:55,330
imsejħa reġistru fil-kompjuter
CPU, li jfisser li huwa super,

757
00:32:55,330 --> 00:32:58,400
super fast, anke fl-inqas
livell ta 'hardware tal-kompjuter.

758
00:32:58,400 --> 00:33:00,530
Allura, hemm biss vantaġġi kollha madwar.

759
00:33:00,530 --> 00:33:01,530
Allura, dak li jfisser dan?

760
00:33:01,530 --> 00:33:04,850
Fil-fatt, meta int tfassil ta '
tabella database, kważi kollha tal-ħin

761
00:33:04,850 --> 00:33:07,170
inti se jkollhom mhux
biss l-informazzjoni li inti care about,

762
00:33:07,170 --> 00:33:09,280
iżda wkoll xi ħaġa bħal
identifikatur uniku

763
00:33:09,280 --> 00:33:11,280
għaliex dan se
ejjew jagħmlu affarijiet oħra.

764
00:33:11,280 --> 00:33:13,160
U ejja vjaġġ fuq problema waħda hawn.

765
00:33:13,160 --> 00:33:15,990
>> Ejja ngħidu li l-utenti ma jkunux
biss usernames u ismijiet,

766
00:33:15,990 --> 00:33:19,540
imma għandhom ukoll affarijiet simili ibliet
u l-istati u l-kodiċi zip, għall-inqas

767
00:33:19,540 --> 00:33:20,432
hawn fl-Istati Uniti.

768
00:33:20,432 --> 00:33:22,390
Allura, jien ser jimxi 'l quddiem
u biss malajr jgħidu,

769
00:33:22,390 --> 00:33:26,180
tagħti me tliet kolonni aktar
fl-aħħar tat-tabella.

770
00:33:26,180 --> 00:33:28,900
U dan se jkun City,
dan se jkun l-Istat,

771
00:33:28,900 --> 00:33:30,400
u dan se tkun Zip.

772
00:33:30,400 --> 00:33:32,710
>> Issa tipi City, liema data
jekk dan ikun, forsi?

773
00:33:32,710 --> 00:33:35,460

774
00:33:35,460 --> 00:33:35,989
Varchar?

775
00:33:35,989 --> 00:33:37,780
I do not know dak l-
itwal belt isem huwa.

776
00:33:37,780 --> 00:33:40,571
X'imkien fl-Amerika, hemm
probabbilment xi kelma ridiculously twal,

777
00:33:40,571 --> 00:33:43,605
so ejja biss jmorru ma '255, kemmxejn
storikament jew b'mod arbitrarju.

778
00:33:43,605 --> 00:33:44,730
Stat, dak li inti trid tagħmel?

779
00:33:44,730 --> 00:33:48,380

780
00:33:48,380 --> 00:33:50,367
Sejħa is-sentenza, id-dritt?

781
00:33:50,367 --> 00:33:51,700
X'hemm forsi l-aktar effiċjenti?

782
00:33:51,700 --> 00:33:53,500
Kif karattri ħafna?

783
00:33:53,500 --> 00:33:55,950
Forsi biss tnejn, jekk nistgħu
jitbiegħed ma tagħmel biss,

784
00:33:55,950 --> 00:33:58,250
bħal, MA għall Massachusetts u oħrajn.

785
00:33:58,250 --> 00:34:00,520
Allura, jien ser imorru valur CHAR ta 'tnejn.

786
00:34:00,520 --> 00:34:03,080
>> Kodiċi zip huwa wieħed interessanti.

787
00:34:03,080 --> 00:34:06,679
Aħna hawn fil 02,138, sabiex
jissuġġerixxi għandna nużaw dak?

788
00:34:06,679 --> 00:34:07,470
Huwa ta 'INT, id-dritt?

789
00:34:07,470 --> 00:34:10,030

790
00:34:10,030 --> 00:34:12,800
INT, INT, qasir?

791
00:34:12,800 --> 00:34:14,521
Short tkun taħdem.

792
00:34:14,521 --> 00:34:15,020
Nru?

793
00:34:15,020 --> 00:34:18,920

794
00:34:18,920 --> 00:34:20,870
CHAR jew ħames, imma nixtieq li INT.

795
00:34:20,870 --> 00:34:23,710
Għaliex timbotta lura fuq INT?

796
00:34:23,710 --> 00:34:26,820
Tipperswadi lili minn dan.

797
00:34:26,820 --> 00:34:29,210
X'hemm stupid madwar INT, idea tiegħi?

798
00:34:29,210 --> 00:34:29,871
Yeah.

799
00:34:29,871 --> 00:34:31,199
>> UDJENZA: Ħu l-memorja aktar.

800
00:34:31,199 --> 00:34:32,909
>> DAVID Malan: Ħu l-memorja aktar.

801
00:34:32,909 --> 00:34:35,310
Erba bytes, imma int
tipproponi zip code

802
00:34:35,310 --> 00:34:39,000
bħala ħames bytes jew xi ħadd kien bħala CHAR,
li jħoss simili eh, li mhux verament

803
00:34:39,000 --> 00:34:39,620
il-każ.

804
00:34:39,620 --> 00:34:40,489
>> Ukoll, storja divertenti.

805
00:34:40,489 --> 00:34:43,179
Snin ilu, meta I użati biex jużaw
Microsoft Outlook għall-email tiegħi,

806
00:34:43,179 --> 00:34:45,150
I eventwalment ridt li jaqilbu għal Gmail.

807
00:34:45,150 --> 00:34:48,949
U hekk, I esportati kollha tiegħi
kuntatti mill-Outlook bħala fajl CSV.

808
00:34:48,949 --> 00:34:50,699
Comma separati valuri,
li ftit fisser I

809
00:34:50,699 --> 00:34:54,060
kellu l-ismijiet ħbieb tiegħi u l-aħħar
ismijiet u numri tat-telefon u l-kodiċi zip

810
00:34:54,060 --> 00:34:54,747
u kollha ta 'dak.

811
00:34:54,747 --> 00:34:56,580
U mbagħad I magħmula l-
żball tal-ftuħ it up

812
00:34:56,580 --> 00:34:58,640
fl-Excel, li hija
programm spreadsheet li

813
00:34:58,640 --> 00:35:00,289
jifhem CSV fajls kif aħna stajt tidher.

814
00:35:00,289 --> 00:35:03,080
Imma mbagħad, I għandu jkollhom hit, bħal,
Kmand jew Control S fuq punt wieħed.

815
00:35:03,080 --> 00:35:06,250
U Excel apparentement fiż-żmien
kellhom karatteristika li biha kwalunkwe ħin li

816
00:35:06,250 --> 00:35:08,100
raw numru, ippruvaw jkun utli.

817
00:35:08,100 --> 00:35:11,610
U jekk dak in-numru beda bil
żerijiet, ikun biss jeħles minnhom.

818
00:35:11,610 --> 00:35:13,420
Għaliex għandek bżonn ewlieni
żerijiet fuq interi?

819
00:35:13,420 --> 00:35:15,140
Huma qed sens, matematikament.

820
00:35:15,140 --> 00:35:17,530
Dawn mhux qed bla sens
fis-sistema US Postali.

821
00:35:17,530 --> 00:35:19,954
So, I kellna għas-snin,
din il-ġurnata, I still

822
00:35:19,954 --> 00:35:22,370
ħbieb li meta l-
każ rari li I bżonn xi ħadd huwa

823
00:35:22,370 --> 00:35:24,078
tindirizza dawn il-ġranet,
I xorta ser tara li I

824
00:35:24,078 --> 00:35:26,767
xi ħabib fil-Cambridge,
Massachusetts, 2138.

825
00:35:26,767 --> 00:35:29,350
U huwa annoying jekk int
jippruvaw biex issolvi tal programmatically

826
00:35:29,350 --> 00:35:30,975
jiġġeneraw pakketti jew eżatt LOGHOME-isfel.

827
00:35:30,975 --> 00:35:33,599
U dan għaliex din ir-raġuni,
I għażlet dejta tat-tip żbaljata.

828
00:35:33,599 --> 00:35:34,490
So, I imħabba l-idea tiegħek.

829
00:35:34,490 --> 00:35:35,650
Ejja jużaw qasam CHAR.

830
00:35:35,650 --> 00:35:38,340
Ħames karattri, ħlief
hemm każ kantuniera.

831
00:35:38,340 --> 00:35:42,220
Jekk inti xorta tibgħat posta,
kultant zip kodiċijiet dawn il-ġranet,

832
00:35:42,220 --> 00:35:45,360
dawn qed, bħal, flimkien ma 'erba.

833
00:35:45,360 --> 00:35:48,200
Għalhekk, għandna bżonn sing u mbagħad
għandna bżonn erba 'numri aktar.

834
00:35:48,200 --> 00:35:50,330
Allura biex ikunu onesti, din tista
mur f'ħafna modi differenti.

835
00:35:50,330 --> 00:35:52,371
>> Għal issa, jien ser iżommu
sempliċi u jien biss

836
00:35:52,371 --> 00:35:54,780
se ngħid li din hija
ħamsa valur CHAR u aħna

837
00:35:54,780 --> 00:35:56,739
ser skip il-sing kollu plus erbgħa.

838
00:35:56,739 --> 00:35:58,280
Iżda dawn huma t-tipi ta 'kompromessi.

839
00:35:58,280 --> 00:36:00,196
U inti tista 'taħseb l-
problemi li jinqalgħu istess

840
00:36:00,196 --> 00:36:01,860
bin-numri tat-telefon jew oqsma oħra.

841
00:36:01,860 --> 00:36:04,350
>> U issa, dan huwa attwalment
triq foolish li jinżlu.

842
00:36:04,350 --> 00:36:08,000
Ejja ngħidu kemm Rob u I u Hannah
u Maria u [? Davon?] U Andy

843
00:36:08,000 --> 00:36:12,820
u oħrajn fuq il-persunal kollu jgħixu
fil Cambridge, Massachusetts, 02138.

844
00:36:12,820 --> 00:36:17,970
Dan attwalment iħossu stupid li jien
li jżid mal-mejda utenti tiegħi, belt, statali,

845
00:36:17,970 --> 00:36:18,630
u ZIP.

846
00:36:18,630 --> 00:36:20,980
Għaliex?

847
00:36:20,980 --> 00:36:21,960
>> UDJENZA: [inaudible]

848
00:36:21,960 --> 00:36:22,918
>> DAVID Malan: Say mill-ġdid?

849
00:36:22,918 --> 00:36:24,310
UDJENZA: [inaudible]

850
00:36:24,310 --> 00:36:25,850
>> DAVID Malan: Huma qed dejjem
se jmorru flimkien, id-dritt?

851
00:36:25,850 --> 00:36:28,660
Meta jirriżulta, aħna użati biex jaħsbu
dan kien il-każ sakemm aħna eżawrjenti

852
00:36:28,660 --> 00:36:30,570
mfittxija l-Istati Uniti kollu,
u jirriżulta li hemmhekk

853
00:36:30,570 --> 00:36:32,653
huma xi inkonsistenzi
fejn bliet multipli jkollhom

854
00:36:32,653 --> 00:36:35,060
l-istess zip, li huwa stramb.

855
00:36:35,060 --> 00:36:40,580
Iżda, jekk irridu jistipulaw għal issa dak 02138
huwa dejjem Cambridge, Massachusetts,

856
00:36:40,580 --> 00:36:44,910
għaliex fid-dinja kieku inti jaħżen fil
database tiegħek Cambridge u MA u 02138

857
00:36:44,910 --> 00:36:49,357
għalija u għal Hannah u għal Rob u
għall [? Davon?] U għal oħrajn li jgħixu

858
00:36:49,357 --> 00:36:51,190
hawn fil Cambridge, huwa
perfettament żejda.

859
00:36:51,190 --> 00:36:54,480
>> Għandna jitbiegħed
mal biss ħażna liema?

860
00:36:54,480 --> 00:36:55,610
Biss il-kodiċi zip.

861
00:36:55,610 --> 00:36:58,660
Iżda mbagħad, jekk aħna maħżen biss il-
zip code, I do jridu, probabbilment,

862
00:36:58,660 --> 00:37:02,160
għall-website tiegħi li tkun taf fejn 02138 hu.

863
00:37:02,160 --> 00:37:03,910
So, I bżonn ieħor tabella.

864
00:37:03,910 --> 00:37:04,697
U li OK.

865
00:37:04,697 --> 00:37:07,530
U fil-fatt, dan huwa wieħed mill-
proċessi ta 'disinn ta' tfassil tabelli

866
00:37:07,530 --> 00:37:11,472
li inti ser tagħmel fil PSet7 kif ukoll permezz tagħha
inti tixtieq li fattur out data komuni.

867
00:37:11,472 --> 00:37:14,430
Eżatt bħal aħna kont qed factoring out
kodiċi u l-fattorar out komuni komuni

868
00:37:14,430 --> 00:37:17,380
stili minn CSS, hawn
wisq fid-database,

869
00:37:17,380 --> 00:37:21,180
jekk għandi bżonn 02138 biss biex unikament
jidentifikaw Hometown xi ħadd,

870
00:37:21,180 --> 00:37:25,020
taħżinx Cambridge, Quddiesa għall
kull utent darn fit-tabella tiegħek.

871
00:37:25,020 --> 00:37:29,770
>> Minflok, jkollhom tabella separata msejħa
Żippijiet li għandu jkollu dak kolonni?

872
00:37:29,770 --> 00:37:33,490
Probabbilment qasam ID, sempliċement minħabba, per
il-prinċipji aħna qed jitkellem dwar issa.

873
00:37:33,490 --> 00:37:35,720
Probabbilment qasam code għall 02138.

874
00:37:35,720 --> 00:37:38,400
U allura probabbilment dak kolonni oħra?

875
00:37:38,400 --> 00:37:42,950
Belt u stat, iżda biss għandek wieħed
ringiela għal 02138, ringiela waħda għal 02139,

876
00:37:42,950 --> 00:37:44,772
ringiela waħda għal 90,210.

877
00:37:44,772 --> 00:37:46,730
U li huwa litteralment
il-kodiċijiet kollha zip naf.

878
00:37:46,730 --> 00:37:49,012
>> Allura issa, dak li tista 'taghmel?

879
00:37:49,012 --> 00:37:51,220
Dan huwa fatt problematiku, minħabba
issa stajt ltqajna żewġ tabelli.

880
00:37:51,220 --> 00:37:54,660
Allura, l-utenti tiegħi huma l-aktar fuq hawn,
iżda l-informazzjoni belt stat tagħhom huwa

881
00:37:54,660 --> 00:37:55,390
minn hawn.

882
00:37:55,390 --> 00:37:58,635
Allura, jirriżulta bl SQL, hemm
fil-fatt mod biex jissieħbu informazzjoni,

883
00:37:58,635 --> 00:38:00,470
u tkun taf tara dan fil-PSet.

884
00:38:00,470 --> 00:38:03,000
>> Iżda jirriżulta li tista
tagħmel xi ħaġa bħal din.

885
00:38:03,000 --> 00:38:10,501
Star Agħżel minn utenti, Jissieħbu zips FUQ
utenti dot zip huwa ugwali zips dot zip.

886
00:38:10,501 --> 00:38:13,360
Li hija wordy ftit,
ċertament, iżda dan biss

887
00:38:13,360 --> 00:38:17,590
tfisser dak kollu Agħżel mill-
proċess tat-teħid tabella utenti tiegħi

888
00:38:17,590 --> 00:38:19,580
u tabella żippijiet tiegħi.

889
00:38:19,580 --> 00:38:22,120
Jingħaqdu magħhom fuq il-wieħed
qasam li jkunu fil-kolonna.

890
00:38:22,120 --> 00:38:24,780
Allura, litteralment tagħmel xi ħaġa
bħal dan, u jagħtu me back

891
00:38:24,780 --> 00:38:27,360
tabella temporanju ġdid
li l-aktar wiesa ', li l-akbar,

892
00:38:27,360 --> 00:38:29,450
li għandu l-
kolonni minn tnejn minnhom.

893
00:38:29,450 --> 00:38:33,510
U li, pjuttost sempliċi, ikun il-
sintassi biex isir xi ħaġa bħal din.

894
00:38:33,510 --> 00:38:35,540
>> Allura, hemm dan l quddiem,
imma hemm għaddej

895
00:38:35,540 --> 00:38:38,950
li jkunu deċiżjonijiet oħra tad-disinn tkun taf
għandhom jagħmlu, mhux biss ma 'indiċijiet

896
00:38:38,950 --> 00:38:40,550
iżda wkoll tmexxija fis-isfidi.

897
00:38:40,550 --> 00:38:43,360
Fil-fatt, hemm sfida
fi kwalunkwe disinn database

898
00:38:43,360 --> 00:38:47,930
li biha kultant żewġ persuni tista 'tixtieq
aċċess għall-istess ringieli tad-database

899
00:38:47,930 --> 00:38:48,530
tabella.

900
00:38:48,530 --> 00:38:51,450
Allura, din hija xi ħaġa li aħna ser
jiltaqgħu fil PSet7 ukoll.

901
00:38:51,450 --> 00:38:54,686
>> Imma ħsibt d naraha
attakk li possibbli fil SQL.

902
00:38:54,686 --> 00:38:56,560
Liema huma wħud mill-
problemi li jistgħu jinqalgħu?

903
00:38:56,560 --> 00:38:58,170
Allura, inti ser tiltaqa dan fil PSet7.

904
00:38:58,170 --> 00:39:01,874
U aħna jgħidlek kollox dak l-
kodifikazzjoni soluzzjoni għal din il-problema hija.

905
00:39:01,874 --> 00:39:04,790
Imma jekk inti tieħu klassi livell ogħla,
speċjalment fis-sistemi operattivi,

906
00:39:04,790 --> 00:39:06,950
int ser jiltaqgħu
kwistjoni ta 'atomicity,

907
00:39:06,950 --> 00:39:10,080
il-problema ta 'tipprova tagħmel
affarijiet multipli kollha f'daqqa

908
00:39:10,080 --> 00:39:11,000
mingħajr interruzzjoni.

909
00:39:11,000 --> 00:39:14,560
>> U ħsibt I d jintroduċu dan
idea għal PSet7 ma metafora

910
00:39:14,560 --> 00:39:18,160
li tgħallimt myself fil Margo
Sistemi operattivi CS164 Seltzer ta

911
00:39:18,160 --> 00:39:18,990
snin klassi ilu.

912
00:39:18,990 --> 00:39:22,230
Ejja ngħidu li għandek wieħed minn dawn dorm
fridges fil-kamra dorm tiegħek jew dar,

913
00:39:22,230 --> 00:39:24,474
u inti għandek penchant reali għall-ħalib.

914
00:39:24,474 --> 00:39:27,140
U għalhekk, inti come home minn klassijiet
ġurnata waħda, inti tiftaħ il-fridge.

915
00:39:27,140 --> 00:39:27,620
Oh, kkritikat dan.

916
00:39:27,620 --> 00:39:28,870
M'hemm l-ebda ħalib fil-friġġ.

917
00:39:28,870 --> 00:39:32,470
Allura, inti qrib il-fridge,
lock-bieb, lock dorm tiegħek,

918
00:39:32,470 --> 00:39:34,770
mixja madwar il-kantuniera
li CVS, jiksbu fil-linja,

919
00:39:34,770 --> 00:39:36,312
u tibda ikkontrollar out għal xi ħalib.

920
00:39:36,312 --> 00:39:38,978
U li għaddej biex tieħu filwaqt li,
minħabba dawk kkritikat checkout awto

921
00:39:38,978 --> 00:39:40,570
counters jieħdu dejjem biex jintuża xorta waħda.

922
00:39:40,570 --> 00:39:41,950
Allura sadanittant, roommate tiegħek jiġi dar.

923
00:39:41,950 --> 00:39:43,470
Hu jew hi verament jħobb ħalib kif ukoll.

924
00:39:43,470 --> 00:39:45,520
Huma jidħlu fil-kamra dorm,
tiftaħ il-fridge, oh, darn dan.

925
00:39:45,520 --> 00:39:46,490
M'hemm l-ebda ħalib aktar.

926
00:39:46,490 --> 00:39:49,040
>> Allura, hu jew hi wkoll
tmur madwar il-kantuniera.

927
00:39:49,040 --> 00:39:51,670
Imma issa, peress li hemm simili żewġ
jew tlieta jew erba CVSes fil-qrib,

928
00:39:51,670 --> 00:39:53,800
jiġri li jmorru lil wieħed mill-
dawk differenti fil-pjazza.

929
00:39:53,800 --> 00:39:55,830
U hekk issa, ftit minuti
aktar tard, tnejn inti

930
00:39:55,830 --> 00:39:58,060
come home u ugh, problema agħar qatt.

931
00:39:58,060 --> 00:40:00,967
Issa għandek ħalib wisq
minħabba li għaddej biex tmur qarsa.

932
00:40:00,967 --> 00:40:03,050
U inti tixtieq ħalib, imma int
ma verament simili ħalib.

933
00:40:03,050 --> 00:40:06,730
>> Allura issa, dan kien jiswa
żball minħabba tnejn inti

934
00:40:06,730 --> 00:40:09,870
ħadet deċiżjoni bbażata fuq l-
qagħda ta 'madwar varjabbli li

935
00:40:09,870 --> 00:40:12,660
kienet fil-proċess ta '
tbiddlet minnek,

936
00:40:12,660 --> 00:40:14,560
l-inizjatur ta 'se tikseb ħalib.

937
00:40:14,560 --> 00:40:17,785
Allura, dak li huwa forsi bniedem
soluzzjoni għal din il-problema?

938
00:40:17,785 --> 00:40:18,660
UDJENZA: [inaudible]

939
00:40:18,660 --> 00:40:19,430
DAVID Malan: Ħalli nota, id-dritt?

940
00:40:19,430 --> 00:40:21,850
Dejjem iħallu nota, jekk int
familjari ma 'dak ispettaklu.

941
00:40:21,850 --> 00:40:23,100
Iva, hemm żewġ of us.

942
00:40:23,100 --> 00:40:25,940
Allura, dejjem iħallu nota, jew
litteralment lock-friġġ

943
00:40:25,940 --> 00:40:28,602
ma 'xi tip ta' katnazz jew
xi ħaġa matul il-quċċata bħal dik.

944
00:40:28,602 --> 00:40:31,310
Iżda li fil-fatt se tkun
problema ewlenija ma 'disinn database,

945
00:40:31,310 --> 00:40:34,710
speċjalment meta inti jista 'jkollok
browsers multipli, laptops multipli,

946
00:40:34,710 --> 00:40:37,450
utenti multipli kollha jippruvaw
jaġġorna l-informazzjoni f'daqqa.

947
00:40:37,450 --> 00:40:40,590
Informazzjoni partikolarment sensittiva
bħal informazzjoni finanzjarja,

948
00:40:40,590 --> 00:40:43,350
li biha bil-stock trading
websajt bħal inti ser tkun bini,

949
00:40:43,350 --> 00:40:47,270
dak jekk inti tixtieq li jiċċekkjaw kemm flus
għandek u mbagħad jekk għandek biżżejjed,

950
00:40:47,270 --> 00:40:48,490
jixtru xi stokk?

951
00:40:48,490 --> 00:40:50,899
>> Imma x'jiġri jekk xi ħadd ieħor li
għandu kont konġunt miegħek

952
00:40:50,899 --> 00:40:52,690
hija simultanjament tipprova
biex jixtru xi stokk?

953
00:40:52,690 --> 00:40:55,190
Allura, hu jew hi iċċekkjar tal-
bilanċ tal-kont, tnejn inti

954
00:40:55,190 --> 00:40:57,540
jiksbu lura l-istess
tweġiba, hemm ebda ħalib.

955
00:40:57,540 --> 00:41:00,580
Jew it-tnejn minnkom tikseb lura l-risposta,
għandek $ 100 fl-kont.

956
00:41:00,580 --> 00:41:04,680
Tnejn inti tipprova tagħmel id-deċiżjoni
li jixtru sehem wieħed ta 'xi stokk kumpanija.

957
00:41:04,680 --> 00:41:06,130
>> U issa, x'jiġri?

958
00:41:06,130 --> 00:41:07,140
Għandek żewġ ishma?

959
00:41:07,140 --> 00:41:08,420
Inti għandek l-ebda ishma?

960
00:41:08,420 --> 00:41:10,320
Problemi bħal li jistgħu jinqalgħu.

961
00:41:10,320 --> 00:41:11,755
Allura, aħna ser jiltaqgħu dak.

962
00:41:11,755 --> 00:41:14,630
SQL attakki injezzjoni, B'xorti tajba,
huma xi ħaġa aħna ser jgħinuk bil-

963
00:41:14,630 --> 00:41:17,430
iżda dawn huma atrociously
komuni f'dawn il-jiem xorta.

964
00:41:17,430 --> 00:41:18,680
Allura, dan huwa biss eżempju.

965
00:41:18,680 --> 00:41:21,290
I jagħmlu ebda pretensjonijiet li
Sistema Harvard PIN hija

966
00:41:21,290 --> 00:41:23,130
vulnerabbli għal dan l-attakk partikolari.

967
00:41:23,130 --> 00:41:24,160
Imxejna ppruvaw.

968
00:41:24,160 --> 00:41:26,120
Iżda, inti taf li aħna
ikollhom kamp bħal dan.

969
00:41:26,120 --> 00:41:29,620
U l-ID Net Yale għandha simili
tfittex iskrin dawn il-jiem.

970
00:41:29,620 --> 00:41:33,190
U jirriżulta, li forsi l-
Sistema PIN hija implimentata fil-PHP.

971
00:41:33,190 --> 00:41:37,050
>> U jekk huwa were-- huwa not-- huma
jista 'jkollhom kodiċi li tidher bħal dan.

972
00:41:37,050 --> 00:41:38,210
Huma għandhom żewġ varjabbli.

973
00:41:38,210 --> 00:41:42,495
Agħtini l-username u password
mill-varjabbli globali post super

974
00:41:42,495 --> 00:41:43,970
li tkellimna dwar preċedenti.

975
00:41:43,970 --> 00:41:47,310
Forsi Harvard għandha query
bħal stilla Agħżel minn utenti

976
00:41:47,310 --> 00:41:50,005
fejn username ugwali li
u password huwa egwali għal dak.

977
00:41:50,005 --> 00:41:51,880
U tinnota li jien biss
pagamnenti fl-użu

978
00:41:51,880 --> 00:41:55,050
in-notazzjoni Brace kaboċċi mill-ieħor
jum, li jfisser biss plagg fil-valur

979
00:41:55,050 --> 00:41:55,550
hawn.

980
00:41:55,550 --> 00:41:57,449
Jien ma jużawx l-
trade mark in kwistjoni teknika.

981
00:41:57,449 --> 00:41:59,240
Jien m'għandi l-ebda tieni
jew argumenti terzi.

982
00:41:59,240 --> 00:42:02,350
Jien biss litteralment
kostruzzjoni l-sekwenza myself.

983
00:42:02,350 --> 00:42:04,930
>> Il-problema, għalkemm, hi li
jekk xi ħadd bħal scroob,

984
00:42:04,930 --> 00:42:09,020
li hija referenza għal film,
zkuk ma xi ħaġa bħal din,

985
00:42:09,020 --> 00:42:11,250
u stajt jitneħħew l-tikek
li normalment tkopri sa

986
00:42:11,250 --> 00:42:14,370
passwords, dak li jekk huwa jkun
partikolarment malizzjużi

987
00:42:14,370 --> 00:42:18,860
u password tiegħu forsi huwa 12345,
Skond il-movie imsejjaħ "Spaceballs,"

988
00:42:18,860 --> 00:42:21,970
imma hu kritiku tipi ta '
kwotazzjoni waħda wara l-ħames,

989
00:42:21,970 --> 00:42:24,790
allura litteralment il-kelma jew
fl-ispazju, u mbagħad kwotazzjoni,

990
00:42:24,790 --> 00:42:29,160
wieħed unquote ugwali wieħed jikkwota,
imma avviż hu titħalla barra dak?

991
00:42:29,160 --> 00:42:32,700
Hu titħalla barra l-kwotazzjoni fuq il-lemin
u hu ma jsirx il-kwotazzjoni fuq ix-xellug.

992
00:42:32,700 --> 00:42:35,170
>> Għaliex jekk dan attakkant
preżunzjoni scroob s

993
00:42:35,170 --> 00:42:38,160
hija li l-persuni li kiteb
dan il-kodiċi PHP ma kinux daqshekk qawwi,

994
00:42:38,160 --> 00:42:42,990
forsi huma biss ikollhom xi wieħed
kwotazzjonijiet madwar il-interpolazzjoni

995
00:42:42,990 --> 00:42:45,210
ta 'varjabbli fl ċineg kaboċċi?

996
00:42:45,210 --> 00:42:48,620
U hekk forsi, huwa seta tip
tal ilestu ħsieb tagħhom

997
00:42:48,620 --> 00:42:53,290
għalihom, iżda b'mod li għaddej
let lilu Hacked fis-sistema PIN.

998
00:42:53,290 --> 00:42:55,310
Fi kliem ieħor, ejja ngħidu
li dan huwa l-kodiċi

999
00:42:55,310 --> 00:42:57,140
u aħna issa plagg fil dak scroob ittajpjat.

1000
00:42:57,140 --> 00:42:58,770
U huwa aħmar, għaliex dan huwa ħażin.

1001
00:42:58,770 --> 00:43:01,310
>> U t-test sottostanti
huwa dak li ittajpjat fil,

1002
00:43:01,310 --> 00:43:05,510
scroob jista trick server Harvard
fi kostruzzjoni mistoqsija SQL

1003
00:43:05,510 --> 00:43:07,440
string li tidher bħal dan.

1004
00:43:07,440 --> 00:43:11,760
Password ugwali 12345 jew wieħed ugwali wieħed.

1005
00:43:11,760 --> 00:43:14,820
Ir-riżultat tagħha, loġikament,
hija li dan se log scroob

1006
00:43:14,820 --> 00:43:18,360
fil jekk password tiegħu hija
12345 jew jekk wieħed ugwali

1007
00:43:18,360 --> 00:43:22,660
waħda, li naturalment huwa dejjem veru,
li jfisser scroob dejjem gets fis.

1008
00:43:22,660 --> 00:43:26,060
>> U għalhekk, il-mod biex jiffissaw
dan, bħal fil-ħafna każijiet,

1009
00:43:26,060 --> 00:43:28,140
tkun li tikteb aktar fid-difiża.

1010
00:43:28,140 --> 00:43:30,390
Biex tuża xi ħaġa bħal tagħna
funzjoni query attwali, li

1011
00:43:30,390 --> 00:43:33,980
tkun taf tara fil PSet7, fejn aħna plug
xi ħaġa bħal kwistjoni jimmarka hawn.

1012
00:43:33,980 --> 00:43:35,980
U l-sbuħija tal-
funzjoni mistoqsija li aħna

1013
00:43:35,980 --> 00:43:40,010
jtik huwa qiegħed jadotta kontra dawn
hekk imsejħa SQL attakki injezzjoni, fejn

1014
00:43:40,010 --> 00:43:44,260
xi ħadd qed tricking kodiċi tiegħek fis
tinjetta kodiċi SQL tiegħu jew tagħha stess.

1015
00:43:44,260 --> 00:43:47,380
Għaliex dak l-funzjoni mistoqsija
aħna nagħtuk fil-fatt se tagħmel,

1016
00:43:47,380 --> 00:43:51,270
jekk inti tuża l-kwistjoni mark sintassi
u t-tieni u t-tielet argument hawn,

1017
00:43:51,270 --> 00:43:54,590
huwa dak li għamlet dan iżid il-
input li l-utenti ma pprovda?

1018
00:43:54,590 --> 00:43:56,060
Dawk backslash kwotazzjonijiet.

1019
00:43:56,060 --> 00:43:58,590
>> Allura, dan jaħrab kwalunkwe potenzjalment
karattri perikolużi.

1020
00:43:58,590 --> 00:44:01,000
Dan jidher stramb issa,
iżda mhux vulnerabbli

1021
00:44:01,000 --> 00:44:03,260
minħabba li ma
jibdlu l-loġika jibqgħalu

1022
00:44:03,260 --> 00:44:06,470
minħabba li password kollu huwa
issa kwotazzjoni waħda li mhux,

1023
00:44:06,470 --> 00:44:07,596
fil-fatt, password scroob s.

1024
00:44:07,596 --> 00:44:09,845
Allura, kien hemm xi ċajt
dwar dan matul is-snin.

1025
00:44:09,845 --> 00:44:12,570
Allura, dan kien ritratt meħud
ta 'xi geek fil-lott ipparkjar

1026
00:44:12,570 --> 00:44:16,620
fejn inti tista 'taf li xi bliet
u stati jippruvaw scan liċenzja tiegħek

1027
00:44:16,620 --> 00:44:19,460
pjanċa li inti kont jew li biljett inti
jekk inti tmur permezz mingħajr, bħal,

1028
00:44:19,460 --> 00:44:20,660
il-ħaġa E-Z adda.

1029
00:44:20,660 --> 00:44:24,490
Allura, din il-persuna preżunt li forsi
il-poplu bil-miktub is-sistema E-Z Pass

1030
00:44:24,490 --> 00:44:28,240
ma kinux daqshekk qawwi, u forsi huma
biss concatenated flimkien string,

1031
00:44:28,240 --> 00:44:32,190
sabiex hu jew hi ma setax b'mod malizzjuż
mhux biss ilestu maħsub tagħhom,

1032
00:44:32,190 --> 00:44:35,150
imma attwalment tesegwixxi kmand ħażina,
li konna mhux imsemmija għadhom,

1033
00:44:35,150 --> 00:44:36,380
imma inti tista 'probabbilment raden.

1034
00:44:36,380 --> 00:44:39,820
Li minbarra iħassru u
daħħal u taġġorna u tagħżel,

1035
00:44:39,820 --> 00:44:43,370
hemm ukoll keyword imsejjaħ qatra,
li letteralment tħassar kollox

1036
00:44:43,370 --> 00:44:45,300
fid-database, li
huwa partikolarment ħażina.

1037
00:44:45,300 --> 00:44:48,760
>> Nistgħu zoom fl fuq dan jekk
huwa ftit iebsa biex tara.

1038
00:44:48,760 --> 00:44:52,300
Dan, issa, hija cartoons famuż
dan huwa wonderfully għaqlija issa

1039
00:44:52,300 --> 00:44:53,145
u li tinftiehem.

1040
00:44:53,145 --> 00:45:00,880

1041
00:45:00,880 --> 00:45:04,750
>> [Rires]

1042
00:45:04,750 --> 00:45:05,910
>> Yeah, berred.

1043
00:45:05,910 --> 00:45:06,800
Tip ta 'geeking out.

1044
00:45:06,800 --> 00:45:08,800
Allura dawn, allura, huma
SQL attakki injezzjoni.

1045
00:45:08,800 --> 00:45:13,050
U dawn qed daqshekk faċli biex jiġi evitat bl-użu
il-kodiċi dritt jew il-libreriji dritt.

1046
00:45:13,050 --> 00:45:15,947
U tkun taf tara fil PSet7, li
għaliex aħna nagħtuk l-funzjoni mistoqsija.

1047
00:45:15,947 --> 00:45:17,780
Allura, ftit teasers
li ħsibna aħna'd

1048
00:45:17,780 --> 00:45:19,930
jagħtuk hawn fil tagħna
minuti fadal flimkien.

1049
00:45:19,930 --> 00:45:24,030
Allura, kif inti tiftakar minn żero ġimgħa, aħna
introduċa dawn iż-żewġ bozoz tad-dawl li

1050
00:45:24,030 --> 00:45:26,610
huma sbieħ, mhux biss minħabba
dawn qed pretty u huma colorful,

1051
00:45:26,610 --> 00:45:29,450
imma għax huma jappoġġjaw xi ħaġa
imsejħa API, Applikazzjoni

1052
00:45:29,450 --> 00:45:31,980
Programmazzjoni Interface U
fil CS50 s'issa, konna

1053
00:45:31,980 --> 00:45:34,440
aktar iffukat fuq IKOLLOK u
POST, iżda jirriżulta

1054
00:45:34,440 --> 00:45:37,390
hemm verbi oħra HTTP bħall PUT.

1055
00:45:37,390 --> 00:45:39,430
>> U fil-fatt, dan kien
slide minn żero ġimgħa

1056
00:45:39,430 --> 00:45:44,930
li biha jekk tikteb kodiċi li jibgħat
a la PSet6 talba HTTP li

1057
00:45:44,930 --> 00:45:49,647
tidher bħal dan ma 'dan blokki ta' test
fil-qiegħ, li huwa msejjaħ JSON,

1058
00:45:49,647 --> 00:45:52,230
jew JavaScript Notazzjoni Għan
li aħna ser nitkellmu dwar ġimgħa d-dieħla,

1059
00:45:52,230 --> 00:45:57,030
inti tista 'ddawar fuq jew itfi jew bidla
il-kulur tad-dwal bħal dawk.

1060
00:45:57,030 --> 00:46:00,480
Mela jekk CS50 wkoll flimkien ma 'xi
ta 'dawk bozoz tad-dawl hawn fi New Haven

1061
00:46:00,480 --> 00:46:02,480
jekk inti tixtieq li tissellef
minnhom għal proġetti finali,

1062
00:46:02,480 --> 00:46:04,370
wkoll xi Microsoft
Bands, li huma simili

1063
00:46:04,370 --> 00:46:07,619
arloġġi li tilbes madwar polz tiegħek
li bl-istess mod ikollhom API sabiex inti

1064
00:46:07,619 --> 00:46:10,040
jistgħu jiktbu software tiegħek stess għalihom.

1065
00:46:10,040 --> 00:46:12,490
>> Għandna kont ma
Apple kodiċi IOS hekk

1066
00:46:12,490 --> 00:46:15,510
li jekk għandek Apple Watch jew
iPhone jew iPad jew iPod,

1067
00:46:15,510 --> 00:46:17,707
inti tista 'tikteb kodiċi li
attwalment timxi fuq dawk.

1068
00:46:17,707 --> 00:46:19,540
Għandna mazz sħiħ
ta Arduinos, li huma

1069
00:46:19,540 --> 00:46:22,010
kompjuters ftit żgħira
mingħajr każijiet, essenzjalment,

1070
00:46:22,010 --> 00:46:25,240
li inti tista 'tqabbad via USB,
tipikament Mac tiegħek jew PC,

1071
00:46:25,240 --> 00:46:28,810
jikteb il-kodiċi li timxi fuq dawn fiżika
apparati li spiss ikollhom sensors fuqhom

1072
00:46:28,810 --> 00:46:30,790
sabiex inti tista 'jinteraġixxu mal-dinja reali.

1073
00:46:30,790 --> 00:46:32,860
Għandna mazz sħiħ
ta 'tagħmir Leap Mozzjoni,

1074
00:46:32,860 --> 00:46:36,500
li huma apparat USB għall MACs u
PCs, hawn u għal darb'oħra, fi New Haven.

1075
00:46:36,500 --> 00:46:40,080
U jekk inti tqabbad lill Mac tiegħek,
inti tista 'attwalment kontroll tal-kompjuter tiegħek

1076
00:46:40,080 --> 00:46:42,550
billi tikteb software
li permezz travi infra-aħmar,

1077
00:46:42,550 --> 00:46:46,360
figuri fl fejn idejn tal-bniedem tiegħek huma,
anki mingħajr ma tmiss it-tastiera tiegħek.

1078
00:46:46,360 --> 00:46:49,135
Ħsibna aħna'd jaqsmu malajr
glimpse għal dan, per eżempju.

1079
00:46:49,135 --> 00:46:51,428
>> [Daqq tal-mużika]

1080
00:46:51,428 --> 00:47:55,840

1081
00:47:55,840 --> 00:47:57,590
Allura, aħna għandna kollha
mazz ta 'dawn l-affarijiet,

1082
00:47:57,590 --> 00:48:01,040
wisq, imsejħa faxex driegħ Myo
li inti tpoġġi fuq driegħ tiegħek

1083
00:48:01,040 --> 00:48:04,595
u allura inti tista 'tikkontrolla l-veru
dinja jew fid-dinja virtwali bħal dan.

1084
00:48:04,595 --> 00:48:06,471
>> [Daqq tal-mużika]

1085
00:48:06,471 --> 00:49:17,580

1086
00:49:17,580 --> 00:49:20,920
Or, irridu wkoll xi Google
Kartun, li huwa litteralment, bħal,

1087
00:49:20,920 --> 00:49:24,841
kaxxa tal-kartun inti tista 'tpoġġi fuq tiegħek
wiċċ, iżda slide fil-telefon ċellulari tiegħek fis dan

1088
00:49:24,841 --> 00:49:27,590
sabiex inti tpoġġi l-tazza tiegħek
telefon verament qrib l-għajnejn tiegħek.

1089
00:49:27,590 --> 00:49:30,190
U Google kartun huwa
pretty irħas fil $ 10 jew $ 20.

1090
00:49:30,190 --> 00:49:32,230
U għandu lentijiet ftit
li ftit off shift

1091
00:49:32,230 --> 00:49:35,900
l-immaġni fuq l-iskrin għall-bniedem tiegħek
għajnejn li jtik sens ta 'fond

1092
00:49:35,900 --> 00:49:39,550
sabiex inti fil-fatt ikollhom 3D
ambjent fuq quddiem tal inti.

1093
00:49:39,550 --> 00:49:42,927
Għandna wkoll xi gear Samsung, li
hija l-verżjoni aktar għaljin ta 'dan,

1094
00:49:42,927 --> 00:49:46,010
iżda li jista 'bl-istess mod slide fi
Telefon android u jagħtuk l-illużjoni

1095
00:49:46,010 --> 00:49:48,309
of-- jew jagħtu l-esperjenza
ta 'realtà virtwali.

1096
00:49:48,309 --> 00:49:50,850
U fil tagħna aħħar żewġ minuti,
ħsibna aħna'd tipprova tagħmel dan.

1097
00:49:50,850 --> 00:49:55,250
Jekk I tista 'proġett liema Colton għandha
hawn biss biex iqabbduk aptit tiegħek,

1098
00:49:55,250 --> 00:49:58,442
let me imorru quddiem u tarmi
up fuq l-iskrin kbira hawn.

1099
00:49:58,442 --> 00:49:59,400
Let me joqtlu l-dwal.

1100
00:49:59,400 --> 00:50:02,290
Colton, do inti tixtieq li tmur quddiem
u mqiegħda fuq ċelluli tiegħek għal mument

1101
00:50:02,290 --> 00:50:05,171
u jiġu fuq matul il
nofs tal-fażi?

1102
00:50:05,171 --> 00:50:07,420
U inti tixtieq li project--
dan huwa dak Colton jara.

1103
00:50:07,420 --> 00:50:10,560
>> Issa, il-Wi-Fi fil hawn huwa
mhux daqshekk qawwi għal dan l-apparat

1104
00:50:10,560 --> 00:50:13,870
li dan huwa super konvinċenti,
iżda Colton huwa litteralment

1105
00:50:13,870 --> 00:50:15,710
f'dan il-post futuristiku maġika.

1106
00:50:15,710 --> 00:50:16,796
Huwa biss jara immaġini waħda.

1107
00:50:16,796 --> 00:50:19,920
Inti tara għajn tax-xellug u tal-lemin tiegħu
li l-moħħ tiegħu huma legatura flimkien

1108
00:50:19,920 --> 00:50:22,260
fi tliet dimensjonijiet
ambjent fuq wiċċu.

1109
00:50:22,260 --> 00:50:24,319
Hu biss magħżul għażla menu hawn.

1110
00:50:24,319 --> 00:50:27,360
U għalhekk għal darb'oħra, hu liebes dan headset
ma 'cell Samsung fuqha dan huwa

1111
00:50:27,360 --> 00:50:29,080
wirelessly jipproġettaw biex overhead tagħna.

1112
00:50:29,080 --> 00:50:30,349
Issa int fuq Mars, I think?

1113
00:50:30,349 --> 00:50:31,140
COLTON: I think so.

1114
00:50:31,140 --> 00:50:32,181
M'inix ċert [inaudible].

1115
00:50:32,181 --> 00:50:34,250
[Rires]

1116
00:50:34,250 --> 00:50:36,374
>> DAVID Malan: Jinstabx
Mars għandha dawn menus.

1117
00:50:36,374 --> 00:50:41,590
>> COLTON: [inaudible] xi jibred
postijiet jekk irridu imorru to--

1118
00:50:41,590 --> 00:50:43,330
>> DAVID Malan: Fejn irridu imorru?

1119
00:50:43,330 --> 00:50:45,837
>> COLTON: [inaudible]

1120
00:50:45,837 --> 00:50:48,170
DAVID Malan: U ejja naraw
fejn l Colton tieħu us issa.

1121
00:50:48,170 --> 00:50:48,961
COLTON: [inaudible]

1122
00:50:48,961 --> 00:50:52,830

1123
00:50:52,830 --> 00:50:56,380
>> DAVID Malan: Allura, hemm tant
postijiet differenti inti tista 'tieħu yourself.

1124
00:50:56,380 --> 00:51:00,590
Hemm FAPIs permezz tiegħu tista '
jiktbu logħob jew interazzjonijiet li

1125
00:51:00,590 --> 00:51:01,950
run, finalment, fuq it-telefon.

1126
00:51:01,950 --> 00:51:03,908
Allura, int verament ftit
kitba ta 'app telefon ċellulari.

1127
00:51:03,908 --> 00:51:06,380
Iżda grazzi għall-software
u l-kapaċitajiet grafika,

1128
00:51:06,380 --> 00:51:08,765
issa Colton Huwa f'dan
cottage ftit żgħira.

1129
00:51:08,765 --> 00:51:10,515
U għar-riskju ta '
joħnoq nfusna,

1130
00:51:10,515 --> 00:51:13,330
Colton u jien ser twaħħal madwar għal
filwaqt li fl-aħħar ta 'klassi hawn illum

1131
00:51:13,330 --> 00:51:14,300
jekk inti tixtieq li toħroġ u play.

1132
00:51:14,300 --> 00:51:16,350
U aħna ser iġibu magħhom
ġimgħa d-dieħla lura kif ukoll.

1133
00:51:16,350 --> 00:51:18,420
Mingħajr aktar, dewmien
din hija għal-lum.

1134
00:51:18,420 --> 00:51:21,990
Aħna ser tara int ġimgħa d-dieħla.

1135
00:51:21,990 --> 00:51:24,140
>> [MUSIC - tewmin ragga, "MAN BAD"]

1136
00:51:24,140 --> 00:55:23,146