DROP TABLE
DROP TABLE 语句用于从当前所选的数据库中删除表。如果表不存在则会报错，除非使用 IF EXISTS 修饰符。
语法图
- DropTableStmt
- OptTemporary
- TableOrTables
- TableNameList
DropTableStmt ::=
'DROP' OptTemporary TableOrTables IfExists TableNameList RestrictOrCascadeOpt
OptTemporary ::=
( 'TEMPORARY' | ('GLOBAL' 'TEMPORARY') )?
TableOrTables ::=
'TABLE'
| 'TABLES'
TableNameList ::=
TableName ( ',' TableName )*
删除临时表
删除普通表和临时表的用法如下：
DROP TEMPORARY TABLE只能删除本地临时表DROP GLOBAL TEMPORARY TABLE只能删除全局临时表DROP TABLE可以删除普通表或临时表
示例
CREATE TABLE t1 (a INT);
Query OK, 0 rows affected (0.11 sec)
DROP TABLE t1;
Query OK, 0 rows affected (0.22 sec)
DROP TABLE table_not_exists;
ERROR 1051 (42S02): Unknown table 'test.table_not_exists'
DROP TABLE IF EXISTS table_not_exists;
Query OK, 0 rows affected, 1 warning (0.01 sec)
SHOW WARNINGS;
+-------+------+---------------------------------------+
| Level | Code | Message |
+-------+------+---------------------------------------+
| Note | 1051 | Unknown table 'test.table_not_exists' |
+-------+------+---------------------------------------+
1 row in set (0.01 sec)
CREATE VIEW v1 AS SELECT 1;
Query OK, 0 rows affected (0.10 sec)
DROP TABLE v1;
Query OK, 0 rows affected (0.23 sec)
MySQL 兼容性
- 目前
RESTRICT和CASCADE仅在语法上支持。