本文介绍如何使用MySQL中的SUM函数对特定条件的数据进行计数，并通过分组查询实现胜利与失败次数的汇总显示。这种方法适用于需要快速统计某个字段中不同值出现次数的情况。
1.巧用sum（）函数
+---------------------+---------+
| date | victory |
+---------------------+---------+
| 2006-05-21 00:00:00 | 败 |
| 2006-05-22 00:00:00 | 胜 |
| 2006-05-21 00:00:00 | 胜 |
| 2006-05-22 00:00:00 | 败 |
| 2006-05-21 00:00:00 | 败 |
| 2006-05-22 00:00:00 | 胜 |
+---------------------+---------+
查询转换成
| date | victory |
+---------------------+---------+
| 2006-05-21 00:00:00 | 败 |
| 2006-05-22 00:00:00 | 胜 |
| 2006-05-21 00:00:00 | 胜 |
| 2006-05-22 00:00:00 | 败 |
| 2006-05-21 00:00:00 | 败 |
| 2006-05-22 00:00:00 | 胜 |
+---------------------+---------+
查询转换成
+---------------------+---------+------+
| date | victory | fail |
+---------------------+---------+------+
| 2006-05-21 00:00:00 | 1 | 2 |
| 2006-05-22 00:00:00 | 2 | 1 |
+---------------------+---------+------+
| date | victory | fail |
+---------------------+---------+------+
| 2006-05-21 00:00:00 | 1 | 2 |
| 2006-05-22 00:00:00 | 2 | 1 |
+---------------------+---------+------+
mysql> select date,sum(victory='胜') as victory ,sum(victory='败') as fail from text group by date;
扫一扫
269
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
