Statements for transaction rollback in sql

Use the ROLLBACK statement to undo changes in uncommitted transactions and restore the database to the state at the beginning of the transaction.

Statements used for transaction rollback in SQL

In SQL, transaction rollback statements are used for undo All changes in uncommitted transactions. It restores the database to the state it was in when the transaction started.

Rollback statement

<code class="sql">ROLLBACK;</code>

Usage

The rollback statement can be executed at any time in the transaction to undo the so far All changes made so far. After performing a rollback, all changes in the transaction are discarded and the database is restored to the state it was in when the transaction began.

When to use

Rollback statements are usually used in the following situations:

• An error or exception is encountered and the transaction cannot be completed.
• The user decided not to commit the transaction.
• Need to undo the changes and revert to the state at the beginning of the transaction.

Example

<code class="sql">BEGIN TRANSACTION;
-- 执行一些 SQL 语句。
ROLLBACK;
-- 事务中的所有更改都被撤销。</code>

Note

• Rollback statements only apply to the currently active transaction. If the rollback statement is executed after the transaction has committed, it has no effect.
• Rollback statements are irreversible. Once executed, it permanently undoes the changes in the transaction.
• Before using the rollback statement, it is recommended to back up the data to prevent any unexpected situations.

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