SQL中TRUNCATE和DELETE的区别是什么?

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当前回答

并不是说截断不记录SQL Server中的任何内容。truncate不记录任何信息,但它记录您触发truncate的表的数据页的释放。

如果在开始时定义事务,则可以回滚被截断的记录,回滚后可以恢复被截断的记录。但不能在提交截断事务后从事务日志备份中恢复截断记录。

其他回答

最大的区别是truncate是不记录日志的操作,而delete是。

简单地说,这意味着在数据库崩溃的情况下,不能通过截断恢复所操作的数据,但可以通过删除恢复。

详情请点击这里

一眨眼的功夫就不能做DDL。

我想对matthieu的帖子发表评论,但我还没有得到代表…

在MySQL中,自动递增计数器通过truncate重置,而不是通过delete重置。

DROP The DROP command removes a table from the database. All the tables' rows, indexes and privileges will also be removed. No DML triggers will be fired. The operation cannot be rolled back. TRUNCATE TRUNCATE removes all rows from a table. The operation cannot be rolled back and no triggers will be fired. As such, TRUNCATE is faster and doesn't use as much undo space as a DELETE. Table level lock will be added when Truncating. DELETE The DELETE command is used to remove rows from a table. A WHERE clause can be used to only remove some rows. If no WHERE condition is specified, all rows will be removed. After performing a DELETE operation you need to COMMIT or ROLLBACK the transaction to make the change permanent or to undo it. Note that this operation will cause all DELETE triggers on the table to fire. Row level lock will be added when deleting.

来自:http://www.orafaq.com/faq/difference_between_truncate_delete_and_drop_commands

DELETE The DELETE command is used to remove rows from a table. A WHERE clause can be used to only remove some rows. If no WHERE condition is specified, all rows will be removed. After performing a DELETE operation you need to COMMIT or ROLLBACK the transaction to make the change permanent or to undo it. Note that this operation will cause all DELETE triggers on the table to fire. TRUNCATE TRUNCATE removes all rows from a table. The operation cannot be rolled back and no triggers will be fired. As such, TRUCATE is faster and doesn't use as much undo space as a DELETE. DROP The DROP command removes a table from the database. All the tables' rows, indexes and privileges will also be removed. No DML triggers will be fired. The operation cannot be rolled back. DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. Therefore DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back.

来自:http://www.orafaq.com/faq/difference_between_truncate_delete_and_drop_commands