Kuv yuav xaiv lub npe kab nrog qhov chaw hauv SQL li cas?

2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47

Yuav ua li cas xaiv ib kab npe nrog qhov chaw hauv MySQL? Xaiv ib kab npe nrog qhov chaw , siv lub cim tom qab nrog npe kem . Lub cim yog (``). Rov qab zuam yog tso tawm nyob rau hauv cov keyboard hauv qab no tus neeg teb xov tooj tilde (~).

Yog li ntawd, SQL kab npe tuaj yeem muaj qhov chaw?

Kuv paub rau SQL ntawv Server peb muaj rooj teb nrog qhov chaw , mas cov npe teb muaj nyob rau hauv lub brackets, zoo li no [ Kem Ib] thiab peb tsis muaj teeb meem. Hauv lwm cov databases, koj ua tau enclose cov teb npe nyob rau hauv cov lus hais thiab tuav qhov chaw.

Qhov thib ob, siv li cas muaj nyob rau hauv SQL? Muaj yog ib tug predicate siv nyob rau hauv qhov chaw ntawm ib tug Transact- SQL ntawv SELECT nqe lus los ua SQL ntawv Server full-text search on full-text indexed columns muaj hom ntaub ntawv raws tus cwj pwm. Muaj tuaj yeem tshawb rau: Ib lo lus lossis kab lus. Lub prefix ntawm ib lo lus los yog kab lus.

Ib yam li ntawd, nws tau nug, MySQL cov npe lub rooj puas muaj qhov chaw?

Ua tau peb tsim ib rooj nrog a qhov chaw hauv npe hauv MySQL ? Tsim ib tug rooj nrog a qhov chaw hauv npe table hauv MySQL , koj yuav tsum siv backticks txwv tsis pub koj yuav tau ib qho yuam kev.

Kuv yuav rename ib kem hauv SQL li cas?

SQL Rename Kem Syntax

1. ALTER TABLE "table_name" Hloov "kem 1" "kem 2" ["Data Type"];
2. ALTER TABLE "table_name" RENAME COLUMN "kem 1" TO "kem 2";
3. ALTER TABLE Cov Neeg Siv Khoom Hloov Chaw Nyob Addr char(50);
4. ALTER TABLE Cov Neeg Siv Khoom RENAME COLUMN Chaw Nyob rau Addr;