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

ShowStmt:

ShowStmt

ShowTargetFilterable:

ShowTargetFilterable

示例

  1. CREATE TABLE t1 (a INT UNSIGNED);
  1. Query OK, 0 rows affected (0.11 sec)
  1. INSERT INTO t1 VALUES (0);
  1. Query OK, 1 row affected (0.02 sec)
  1. SELECT 1/a FROM t1;
  1. +------+
  2. | 1/a |
  3. +------+
  4. | NULL |
  5. +------+
  6. 1 row in set, 1 warning (0.00 sec)
  1. SHOW WARNINGS;
  1. +---------+------+---------------+
  2. | Level | Code | Message |
  3. +---------+------+---------------+
  4. | Warning | 1365 | Division by 0 |
  5. +---------+------+---------------+
  6. 1 row in set (0.00 sec)
  1. INSERT INTO t1 VALUES (-1);
  1. ERROR 1264 (22003): Out of range value for column 'a' at row 1
  1. SELECT * FROM t1;
  1. +------+
  2. | a |
  3. +------+
  4. | 0 |
  5. +------+
  6. 1 row in set (0.00 sec)
  1. SET sql_mode='';
  1. Query OK, 0 rows affected (0.00 sec)
  1. INSERT INTO t1 VALUES (-1);
  1. Query OK, 1 row affected, 1 warning (0.01 sec)
  1. SHOW WARNINGS;
  1. +---------+------+---------------------------+
  2. | Level | Code | Message |
  3. +---------+------+---------------------------+
  4. | Warning | 1690 | constant -1 overflows int |
  5. +---------+------+---------------------------+
  6. 1 row in set (0.00 sec)
  1. SELECT * FROM t1;
  1. +------+
  2. | a |
  3. +------+
  4. | 0 |
  5. | 0 |
  6. +------+
  7. 2 rows in set (0.00 sec)

MySQL 兼容性

SHOW WARNINGS 语句与 MySQL 完全兼容。如有任何兼容性差异,请在 GitHub 上提交 issue

另请参阅