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

mysql> CREATE TABLE t1 (a INT UNSIGNED);
Query OK, 0 rows affected (0.11 sec)

mysql> INSERT INTO t1 VALUES (0);
Query OK, 1 row affected (0.02 sec)

mysql> SELECT 1/a FROM t1;
+------+
| 1/a  |
+------+
| NULL |
+------+
1 row in set, 1 warning (0.00 sec)

mysql> SHOW WARNINGS;
+---------+------+---------------+
| Level   | Code | Message       |
+---------+------+---------------+
| Warning | 1365 | Division by 0 |
+---------+------+---------------+
1 row in set (0.00 sec)

mysql> INSERT INTO t1 VALUES (-1);
ERROR 1264 (22003): Out of range value for column 'a' at row 1
mysql> SELECT * FROM t1;
+------+
| a    |
+------+
|    0 |
+------+
1 row in set (0.00 sec)

mysql> SET sql_mode='';
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO t1 VALUES (-1);
Query OK, 1 row affected, 1 warning (0.01 sec)

mysql> SHOW WARNINGS;
+---------+------+---------------------------+
| Level   | Code | Message                   |
+---------+------+---------------------------+
| Warning | 1690 | constant -1 overflows int |
+---------+------+---------------------------+
1 row in set (0.00 sec)

mysql> 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。如有任何兼容性差异,请在 GitHub 上提交 issue

另请参阅