mysql语句中if语句详解数据库

sql语句中if语句。

先看一下数据库中的数据：

mysql> select * from student order by class ,score;

+----+-------+-------+-------+ 
| id | name  | class | score | 
+----+-------+-------+-------+ 
|  2 | user  |     1 |    45 | 
|  4 | user  |     1 |    62 | 
|  3 | user1 |     1 |    80 | 
|  1 | user1 |     1 |   100 | 
|  5 | user1 |     1 |   100 | 
|  8 | user  |     2 |    24 | 
|  7 | user1 |     2 |    90 | 
|  6 | user  |     2 |   108 | 
+----+-------+-------+-------+ 
8 rows in set (0.00 sec)

if语句结果：

mysql> SELECT class,sum(IF(score>60,1,0)) JIGE ,sum(IF(score<60,1,0)) BUJIGE FROM student GROUP BY class ;

输出结果：

 
+-------+------+--------+ 
| class | JIGE | BUJIGE | 
+-------+------+--------+ 
|     1 |    4 |      1 | 
|     2 |    2 |      1 | 
+-------+------+--------+ 
2 rows in set (0.00 sec)

打完收工！