title | summary | aliases | ||
---|---|---|---|---|
DROP TABLE |
TiDB 数据库中 DROP TABLE 的使用概况。 |
|
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。
DropTableStmt ::=
'DROP' OptTemporary TableOrTables IfExists TableNameList RestrictOrCascadeOpt
OptTemporary ::=
( 'TEMPORARY' | ('GLOBAL' 'TEMPORARY') )?
TableOrTables ::=
'TABLE'
| 'TABLES'
TableNameList ::=
TableName ( ',' TableName )*
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
{{< copyable "sql" >}}
CREATE TABLE t1 (a INT);
Query OK, 0 rows affected (0.11 sec)
{{< copyable "sql" >}}
DROP TABLE t1;
Query OK, 0 rows affected (0.22 sec)
{{< copyable "sql" >}}
DROP TABLE table_not_exists;
ERROR 1051 (42S02): Unknown table 'test.table_not_exists'
{{< copyable "sql" >}}
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)
{{< copyable "sql" >}}
CREATE VIEW v1 AS SELECT 1;
Query OK, 0 rows affected (0.10 sec)
{{< copyable "sql" >}}
DROP TABLE v1;
Query OK, 0 rows affected (0.23 sec)
- 目前
RESTRICT
和CASCADE
仅在语法上支持。