sql grouping用法

示例代码如下：

DECLARE @t TABLE(Groups char(2),Item varchar(10),Color varchar(10),Quantity int)
INSERT @t SELECT 'aa','Table','Blue', 124
UNION ALL SELECT 'bb','Table','Red',  -23
UNION ALL SELECT 'bb','Cup'  ,'Green',-23
UNION ALL SELECT 'aa','Chair','Blue', 101
UNION ALL SELECT 'aa','Chair','Red',  -90

--汇总显示
SELECT Groups=CASE 
        WHEN GROUPING(Color)=0 THEN Groups
        WHEN GROUPING(Groups)=1 THEN '总计'
        ELSE '' END,
    Item=CASE 
        WHEN GROUPING(Color)=0 THEN Item
        WHEN GROUPING(Item)=1 AND GROUPING(Groups)=0 THEN Groups+' 合计'
        ELSE '' END,
    Color=CASE 
        WHEN GROUPING(Color)=0 THEN Color
        WHEN GROUPING(Color)=1 AND GROUPING(Item)=0 THEN Item+' 小计'
        ELSE '' END,
    Quantity=SUM(Quantity)
FROM @t
GROUP BY Groups,Item,Color WITH ROLLUP
/*--结果
Groups Item       Color           Quantity    
-------- ---------------- ---------------------- ----------- 
aa     Chair      Blue            101
aa     Chair      Red             -90
                 Chair 小计       11
aa     Table      Blue            124
                 Table 小计       124
       aa 合计                    135
bb     Cup        Green           -23
                  Cup 小计        -23
bb     Table      Red             -23
                 Table 小计       -23
       bb 合计                    -46
总计                              89
--*/