4 Txoj hauv Kev Rho Tawm Cov Ntaub Ntawv Dua Zaum Hauv Oracle

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2024 Tus sau: Jason Gerald | [email protected]. Kawg hloov kho: 2024-02-02 14:56

Thaum ua haujlwm hauv Oracle, koj tuaj yeem pom cov ntawv theej ntawm qee cov ntaub ntawv. Koj tuaj yeem tshem tawm cov kab sib tshooj los ntawm kev txheeb xyuas lawv thiab siv RowID lub npe tsis sib xws nyob hauv kab. Ua ntej pib, tsim lub rooj thaub qab yog tias koj xav tau kev siv tom qab cov ntaub ntawv raug tshem tawm.

Kauj ruam

Txoj Kev 1 ntawm 4: Txheeb Xyuas Cov Luam

Kauj Ruam 1. Txheeb xyuas qhov sib thooj

Hauv qhov piv txwv no, peb txheeb xyuas qhov sib tshooj "Alan". Nco ntsoov tias cov ntaub ntawv yuav raug tshem tawm yog qhov tseeb los ntawm kev nkag mus rau SQL hauv qab no.

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 2

Kauj Ruam 2. Txheeb xyuas los ntawm kab ntawv hu ua "Lub Npe"

Yog tias kab ntawv muaj lub npe "Npe", koj yuav tsum hloov "column_name" nrog Lub Npe.

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 3

Kauj Ruam 3. Txheeb xyuas lwm kab ntawv

Yog tias koj tab tom sim txheeb xyuas cov ntawv sib txawv los ntawm kab sib txawv, piv txwv li Alan lub hnub nyoog tsis yog nws lub npe, nkag mus "Hnub Nyoog" hloov chaw ntawm "column_name" thiab ntxiv rau.

xaiv column_name, suav (column_name) los ntawm pawg pawg los ntawm column_name muaj suav (column_name)> 1;

Txoj Kev 2 ntawm 4: Tshem Tawm Ib Leeg

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 4

Kauj Ruam 1. Xaiv "npe los ntawm cov npe"

Tom qab "SQL" (luv rau Standard Query Language), sau "xaiv lub npe los ntawm cov npe".

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 5

Kauj Ruam 2. Rho tawm txhua kab nrog cov npe sib txawv

Tom qab "SQL", nkag mus "rho tawm ntawm cov npe nyob qhov twg lub npe = 'Alan';" Nws yuav tsum tau sau tseg tias kev nqis peev tseem ceeb ntawm no yog li cov kauj ruam no tuaj yeem tshem tawm txhua txoj kab npe "Alan". Tom qab "SQL", nkag mus "cog lus"

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 6

Kauj Ruam 3. Rov ua dua kab uas tsis muaj qhov sib thooj

Tam sim no koj tau tshem tag nrho cov kab thiab hloov lawv nrog "Alan", sau ib qho rov qab los ntawm kev nkag mus "ntxig rau hauv lub npe qhov tseem ceeb ('Alan');" Tom qab "SQL", nkag mus "cog lus" los tsim kab tshiab.

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 7

Kauj Ruam 4. Saib cov npe tshiab

Tom qab ua tiav cov theem saum toj no, koj tuaj yeem tshawb xyuas kom ntseeg tau tias tsis muaj cov ntaub ntawv theej tawm los ntawm kev nkag mus "xaiv * los ntawm cov npe".

SQL> xaiv lub npe los ntawm cov npe; Npe ------------------------------ Alan Citra Tomi Alan Baris xaiv. SQL> rho tawm ntawm cov npe nyob qhov twg lub npe = 'Alan'; Kab ntawv raug tshem tawm. SQL> cog lus; / Ua kom tiav. SQL> ntxig rau hauv cov npe qhov tseem ceeb ('Alan'); kab tsim. SQL> cog lus; Ua tiav. SQL> xaiv * los ntawm cov npe; Npe ------------------------------ Alan Citra Tomi kab xaiv.

Txoj Kev 3 ntawm 4: Tshem Tawm Ntau Yam Luam

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 8

Kauj Ruam 1. Xaiv RowID koj xav rho tawm

Tom qab "SQL", sau "xaiv rowid, npe los ntawm cov npe;."

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 9

Kauj Ruam 2. Tshem cov ntawv theej tawm

Tom qab "SQL", sau "rho tawm ntawm cov npe nyob qhov twg rowid> (xaiv min (rowid) los ntawm cov npe b qhov twg b.name = a.name);" kom tshem tawm cov theej tawm.

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 10

Kauj Ruam 3. Txheeb xyuas qhov sib thooj

Tom qab ua tiav cov theem saum toj no, txheeb xyuas qhov sib tshooj los ntawm kev nkag mus "xaiv kab, npe los ntawm cov npe;" ces "cog lus".

SQL> xaiv rowid, npe los ntawm cov npe; ROWID NPE ------------------------------- AABJnsAAGAAAdfOAAA Alan AABJnsAAGAAAdfOAAB Alan AABJnsAAGAAAdfOAAC Carrie AABJnsAAGAAAdfOAAD Tom AABJnsAAGAAAdfOAAF Alan kab xaiv. SQL> rho tawm ntawm cov npe nyob qhov twg rowid> (xaiv min (rowid) los ntawm cov npe b qhov twg b.name = a.name); kab deleted. SQL> xaiv rowid, npe los ntawm cov npe; ROWID NPE ------------------------------- AABJnsAAGAAAdfOAAA Alan AABJnsAAGAAAdfOAAC Carrie AABJnsAAGAAAdfOAAD Tom kab xaiv. SQL> cog lus; Ua tiav.

Txoj Kev 4 ntawm 4: Tshem Tawm Kab ntawm Kab

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 11

Kauj Ruam 1. Xaiv kab

Tom qab "SQL", sau "xaiv * los ntawm cov npe;" kom tuaj yeem pom kab.

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 12

Kauj Ruam 2. Tshem cov kab sib tshooj los ntawm kev txheeb xyuas lawv cov kab

Tom qab "SQL" sau "rho tawm ntawm cov npe nyob qhov twg rowid> (xaiv min (rowid) los ntawm cov npe b qhov twg b.name = a.name thiab b.age = a.age);" kom tshem tawm cov ntaub ntawv theej tawm.

Rho tawm Cov Ntawv Teev Npe Hauv Oracle Kauj Ruam 13

Kauj Ruam 3. Txheeb xyuas qhov sib thooj

Thaum koj tau ua tiav cov theem saum toj no, nkag mus "xaiv * los ntawm cov npe;" tom qab ntawd "cog lus" txhawm rau saib yog tias cov theej tawm tau raug tshem tawm tiag.

SQL> xaiv * los ntawm cov npe; Lub Npe Hnub Nyoog ------------------------------ ---------------------- Alan 50 Citra 51 Tomi 52 Alan 50 kab xaiv. SQL> rho tawm ntawm cov npe nyob qhov twg rowid> (xaiv min (rowid) los ntawm cov npe b qhov twg b.name = a.name thiab b.age = a.age); kab deleted. SQL> xaiv * los ntawm cov npe; NPE AGE ------------------------------------------ Alan 50 Citra 51 Tomi 52 kab ntawv xaiv. SQL> cog lus; Ua tiav.


Ceeb toom


Tsim cov lus sib dhos hauv koj tus ID nkag mus kom nws tuaj yeem siv ua cov ntsiab lus siv thaum tsis muaj cov ntaub ntawv raug tshem tawm (yog tias koj muaj lus nug).
SQL> tsim cov lus alan.names_backup raws li xaiv * los ntawm cov npe; Rooj tsim.

Pom zoo:

3 Txoj Hauv Kev Hloov Cov Ntaub Ntawv Tiv Thaiv Cov Suab rau hauv MP3 Cov Ntaub Ntawv Li Cas

Thaum ntxov ntawm cov khw muag nkauj hauv internet, DRM lossis Digital Rights Management yog txoj hauv kev zoo los tiv thaiv lwm tus los ntawm kev luam lawv cov nkauj. Txawm li cas los xij, qhov no muab nws tus kheej qhov tsis zoo vim tias ntau tus neeg siv tsuas tuaj yeem ua si lossis mloog lawv cov nkauj los ntawm lawv tus kheej cov cuab yeej.

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Nrog cov ntaub ntawv PDF, koj tuaj yeem tswj hwm qhov qub ntawm daim ntawv thiab qhib cov ntawv ntawm yuav luag txhua lub khoos phis tawj. Xyoo dhau los, nws tau dhau los ua yooj yim los tsim cov ntawv PDF los ntawm cov ntawv sau vim tias ntau qhov haujlwm tau tsim ua hauv PDF tsim cov yam ntxwv.

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Muaj ntau txoj hauv kev rau rov siv cov khaub ncaws qub qub los yog khaub ncaws nraus rau hauv cov ntaub pua tsev. Yog tias peb tuaj yeem dhau los ua tus phooj ywg ib puag ncig, txawj ntse, thiab muaj tswv yim tsim tib neeg, vim li cas ho tsis?

7 Txoj hauv Kev Rho Tawm Cov Ntaub Ntawv Tshem Tawm

Qhov wikiHow qhia koj li cas kom tshem tawm cov ntawv uas tsis tuaj yeem tshem tawm ntawm koj lub computer. Feem ntau, cov ntaub ntawv tsis tuaj yeem raug tshem tawm vim nws tau siv los ntawm cov haujlwm lossis kev pabcuam. Txhawm rau ua haujlwm ib puag ncig cov teeb meem no, koj tuaj yeem siv lub khoos phis tawj nyob rau hauv Safe Mode los tiv thaiv cov haujlwm thiab cov kev pabcuam uas siv cov ntaub ntawv los ntawm kev khiav.

3 Txoj Hauv Kev Yuav Rho Tawm Cov Ntaub Ntawv lossis Cov Ntawv Qhia Qhia "Nkag Mus Tsis Pom Zoo" Cov Lus

Tej zaum koj tau ntsib qhov no. Thaum koj sim rho tawm cov ntawv, cov lus yuam kev tshwm sim uas hais tias: Tsis tuaj yeem tshem tawm: Kev nkag mus raug tsis pom zoo. ' Nco ntsoov tias daim disk tsis puv lossis tiv thaiv kev sau thiab cov ntaub ntawv tsis tau siv tam sim no.