SHOW WARNINGS

SHOW WARNINGS 语句用于显示当前客户端连接中已执行语句的报错列表。与在 MySQL 中一样,sql_mode 极大地影响哪些语句会导致错误与警告。

语法图

ShowWarningsStmt
SHOWWARNINGS

示例

CREATE TABLE t1 (a INT UNSIGNED);
Query OK, 0 rows affected (0.11 sec)
INSERT INTO t1 VALUES (0);
Query OK, 1 row affected (0.02 sec)
SELECT 1/a FROM t1;
+------+ | 1/a | +------+ | NULL | +------+ 1 row in set, 1 warning (0.00 sec)
SHOW WARNINGS;
+---------+------+---------------+ | Level | Code | Message | +---------+------+---------------+ | Warning | 1365 | Division by 0 | +---------+------+---------------+ 1 row in set (0.00 sec)
INSERT INTO t1 VALUES (-1);
ERROR 1264 (22003): Out of range value for column 'a' at row 1
SELECT * FROM t1;
+------+ | a | +------+ | 0 | +------+ 1 row in set (0.00 sec)
SET sql_mode='';
Query OK, 0 rows affected (0.00 sec)
INSERT INTO t1 VALUES (-1);
Query OK, 1 row affected, 1 warning (0.01 sec)
SHOW WARNINGS;
+---------+------+---------------------------+ | Level | Code | Message | +---------+------+---------------------------+ | Warning | 1690 | constant -1 overflows int | +---------+------+---------------------------+ 1 row in set (0.00 sec)
SELECT * FROM t1;
+------+ | a | +------+ | 0 | | 0 | +------+ 2 rows in set (0.00 sec)

MySQL 兼容性

SHOW WARNINGS 语句与 MySQL 完全兼容。如发现任何兼容性差异,请尝试 TiDB 支持资源

另请参阅

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