简单的MAX
查询:
SELECT MAX(Group) FROM acme
在数字列上工作正常。
是否可以在字母数字列上使用它并忽略除数字之外的任何内容?
最佳答案
是的,如果你像这样在使用之前转换它
mysql> SELECT MAX(CAST("123" AS UNSIGNED));
+------------------------------+
| MAX(CAST("123" AS UNSIGNED)) |
+------------------------------+
| 123 |
+------------------------------+
1 row in set (0.00 sec)
mysql> SELECT MAX(CAST("abc" AS UNSIGNED));
+------------------------------+
| MAX(CAST("abc" AS UNSIGNED)) |
+------------------------------+
| 0 |
+------------------------------+
1 row in set, 1 warning (0.00 sec)
mysql> SELECT MAX(CAST("-123" AS SIGNED));
+-----------------------------+
| MAX(CAST("-123" AS SIGNED)) |
+-----------------------------+
| -123 |
+-----------------------------+
1 row in set (0.00 sec)
将字符串列名称替换为“abc”,并根据您的要求修改查询
关于MySQL 字母数字列上的 MIN 和 MAX,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38228544/