假设我有一个包含以下内容的表格:
mysql> select * from test;
+----+------+
| id | val |
+----+------+
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 2 |
| 7 | 2 |
| 8 | 2 |
+----+------+
8 rows in set (0.00 sec)
mysql>
现在我运行了一个错误的SQL查询,使用了group by
子句并且没有对id
列进行任何聚合操作,结果得到了错误的结果:
mysql> select id, val from test group by val;
+----+------+
| id | val |
+----+------+
| 1 | 1 |
| 5 | 2 |
+----+------+
2 rows in set (0.00 sec)
mysql>
MySQL客户端或者其他工具能否验证使用group by
时未进行聚合操作,并对此发出错误或警告?