Question

我正在尝试从表中选择除分组数据的最后一行以外的所有行。

+----+--------+--------+                    +----+--------+--------+
| id | userID | amount |                    | id | userID | amount |
+----+--------+--------+                    +----+--------+--------+
| 1  | 20     | 400    |                    | 1  | 20     | 400    |
+----+--------+--------+                    +----+--------+--------+
| 2  | 20     | 200    |                    | 2  | 20     | 200    |
+----+--------+--------+          =>        +----+--------+--------+
| 3  | 21     | 100    |                    | 3  | 21     | 100    |
+----+--------+--------+                    +----+--------+--------+
| 4  | 11     | 500    |                    | 4  | 11     | 500    |
+----+--------+--------+                    +----+--------+--------+
| 5  | 11     | 250    |                    | 6  | 21     | 50     |
+----+--------+--------+                    +----+--------+--------+
| 6  | 21     | 50     |                    
+----+--------+--------+
| 7  | 20     | 100    |                    
+----+--------+--------+
| 8  | 21     | 200    |
+----+--------+--------+

我尝试使用查询

SELECT * FROM table WHERE userID != (SELECT MAX(userID) FROM table) GROUP BY userID

但是它只获取一行唯一的数据，即使还有更多的数据

Answer 1

您没有聚集功能，因此不需要分组依据

SELECT * 
FROM table 
WHERE userID != ( 
  SELECT MAX(userID) FROM table
)

在mysql版本<5.7（对于mysql版本> 5.7）（默认设置）下，使用group by会引起错误

Answer 2

例如...

SELECT a.*
  FROM my_table a
  LEFT
  JOIN
     ( SELECT MAX(id) id 
         FROM my_table
        GROUP 
           BY userid 
     ) b
    ON b.id = a.id 
 WHERE b.id IS NULL

从表中的分组记录中选择除最后一条记录以外的所有记录

2 个答案: