Puas yog DML Autocommit?
Puas yog DML Autocommit?

Video: Puas yog DML Autocommit?

Video: Puas yog DML Autocommit?
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Anonim

Raws li lub neej ntawd, a DML nqe lus ua tiav yam tsis tau pib qhov kev hloov pauv tau txiav txim siab ua tiav lossis rov qab ua tsis tiav thaum kawg ntawm nqe lus. Tus cwj pwm no hu ua autocommit . Tus cwj pwm no yog tswj nrog lub AUTOCOMMIT parameter.

Ntawm no, DDL puas yog Autocommit?

Ib nqe lus SQL tau ua hauv autocommit modecan tsis tau dov rov qab. Feem ntau DBMS (xws li MariaDB) quab yuam autocommit rau txhua tus DDL nqe lus txawm tias innon- autocommit hom. Ua ntej DDL nqe lus pib ua ntej DML nqe lus hauv kev sib pauv yog (auto) cog lus. Txhua DDL raug tua hauv tus kheej tshiab autocommit kev pauv nyiaj.

Tsis tas li ntawd, yog SQL Server Autocommit? Autocommit hom yog lub neej ntawd kev lag luam kev tswj hwm hom ntawm lub SQL Server Database Cav. Txhua Qhov Kev Ua Haujlwm- SQL ntawv nqe lus tau cog lus los yog dov rov qab thaum nws ua tiav.

Hauv qhov no, DML cov lus tuaj yeem rov qab tau?

Cov nyhuv ntawm a DML lus tsis tas mus li kom txog thaum koj ua qhov kev sib pauv uas suav nrog nws. Kev hloov pauv yog ib ntus ntawm SQL nqe lus uas Oracle Database kho asa unit (nws ua tau ua ib leeg DML lus ). Kom txog thaum atransaction tau cog lus, nws ua tau ua dov rov qab (rov qab).

Puas yog truncate yuav tsum tau cog lus?

Thiab lub ntsiab lus tseem ceeb - txawm hais tias TRUNCATE TABLE zoo li DELETE tsis muaj qhov twg, TRUNCATE tsis yog DML, itis DDL. DELETE xav tau a COMMIT , mas TRUNCATEdoes tsis yog.

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