删除和截断的区别
1。DELETE : DELETE 是一个 DML(数据操作语言)命令，在我们指定要从表或关系中删除的行(元组)时使用。DELETE 命令可以包含一个 WHERE 子句。如果 WHERE 子句与 DELETE 命令一起使用，那么它只删除或删除那些满足条件的行(元组)，否则默认情况下，它从表中删除所有元组(行)。
DELETE 命令语法:
DELETE FROM TableName
WHERE condition;
2。TRUNCATE : TRUNCATE 是一个 DDL(数据定义语言)命令，用于删除表中的所有行或元组。与 DELETE 命令不同，TRUNCATE 命令不包含 WHERE 子句。在 TRUNCATE 命令中，会记录每个已删除数据页的事务日志。与 DELETE 命令不同，TRUNCATE 命令速度很快。在使用 TRUNCATE 命令后，我们无法回滚数据。
TRUNCATE 命令的语法:-
TRUNCATE TABLE TableName;
让我们看看 DELETE 和 TRUNCATE 命令之间的区别:-
| S.NO | delete | cut off | | --- | --- | --- | | 1。 | The DELETE command is used to delete a specified row (one or more rows). | This command is used to delete all rows in the table. | | 2。 | Is a DML (data manipulation language) command. | Although it is a DDL (Data Definition Language) command. | | 3。 | In order to filter records, there may be a WHERE clause in the DELETE command. | There may be no WHERE clause in TRUNCATE command. | | 4。 | In the DELETE command, a tuple is locked before being removed. | In this command, the data page is locked before the table data is removed. | | 5。 | DELETE statement deletes one row at a time and records an entry in the transaction log for each deleted row. | TRUNCATE TABLE removes data by deallocating data pages used to store table data, and only the page deallocation is recorded in the transaction log. | | 6。 | The DELETE command is slower than the TRUNCATE command. | The TRUNCATE command is faster than the DELETE command. | | 7。 | To use delete, you need to have delete permission on the table. | To use Truncate on a table, we need at least ALTER permission on the table. | | 8。 | After using the DELETE statement in the table, the identity of the column retains the identity. | If the table contains an identity column, the identity of the column will be reset to its seed value. | | 9。 | Delete view that can be used for index. | Truncate cannot be used for indexed views. |版权属于：月萌API www.moonapi.com，转载请注明出处
