需要SQL select查询帮助

Question

我的问题类似于SQL select Group查询.但架构有变化,我想要不同的结果,如下所述.给定链接的解决方案并没有给我正确的解决方案.您可以使用SQL小提琴来解决此问题.

下面是我的表

表格1

+--------+----------+---------+  
| amount | make     | product |  
+--------+----------+---------+  
|    100 | Nokia    | Mobiles |   
|    300 | Samesung | Mobiles |   
|    700 | Micromax | Mobiles |   
|   1000 | Karbonn  | Mobiles |   
|    300 | Lava     | Mobiles |   
|    100 | Floyer   | Gift    |   
|    500 | Arichies | Gift    |   
|    300 | Feeling  | Gift    |   
+--------+----------+---------+  

现在我想显示每个产品的两个最低金额,如果金额相同,则根据make列的升序字母顺序排列任何人...

所以我想构建单个SQL查询,它给出了如下结果.

+--------+----------+---------+  
| amount | make     | product |  
+--------+----------+---------+  
|    100 | Nokia    | Mobiles |   
|    300 | Lava     | Mobiles |   
|    100 | Floyer   | Gift    |   
|    300 | Feeling  | Gift    |   
+--------+----------+---------+ 

请帮我构建这样的查询..

Answer 1

这应该对你有帮助..

第一个有bug，现在已经更新了。

SELECT  t.*
FROM    (
    SELECT  @lim := 2,
            @cg := ''
    ) vars,
    (select * from Table1 order by product,amount, make)  t
WHERE   CASE WHEN @cg <> product THEN @r := @lim ELSE 1 END > 0
    AND (@r := @r - 1) >= 0
    AND (@cg := product) IS NOT NULL
ORDER BY
    product,amount, make

享受它和小提琴手的乐趣： http://sqlfiddle.com/#!2 /bdd1a/115/0