GROUPING
是一个聚合函数,它产生一个附加的列，当用 CUBE 或 ROLLUP 运算符添加行时，附加的列输出值为1，当所添加的行不是由 CUBE 或 ROLLUP 产生时，附加列值为0。
仅在与包含 CUBE 或 ROLLUP 运算符的 GROUP BY 子句相联系的选择列表中才允许分组。
语法
GROUPING ( column_name )
参数
column_name
是 GROUP BY 子句中用于检查 CUBE 或 ROLLUP 空值的列。
返回类型
int
--首先创建测试表、添加数据
create table #t(a int,b int,c int,d int,e int)
insert into #t values(1,2,3,4,5)
insert into #t values(1,2,3,4,6)
insert into #t values(1,2,3,4,7)
insert into #t values(1,2,3,4,8)
insert into #t values(1,3,3,4,5)
insert into #t values(1,3,3,4,6)
insert into #t values(1,3,3,4,8)
insert into #t values(1,3,3,4,7)
insert into #t values(2,2,2,4,5)
insert into #t values(2,2,3,4,6)
insert into #t values(2,2,4,4,7)
insert into #t values(2,2,5,4,8)
insert into #t values(2,3,6,4,5)
insert into #t values(2,3,3,4,6)
insert into #t values(2,3,3,4,8)
insert into #t values(2,3,3,4,7)
select *from #t
--情况一：只有一个分类汇总列时，只需要一个合计。只需要增加with rollup即可
select case when grouping(a)=1 then '合计' else cast(a as varchar) end a,
sum(b),sum(c),sum(d),sum(e) from #t group by a with rollup
--情况二:有多个分类汇总列，只需要一个合计.增加rollup之后，需要增加判断。
select case when grouping(a)=1 then '合计' else cast(a as varchar) end a,
b,
sum(c),sum(d),sum(e) from #t
group by a,b with rollup
having grouping(b)=0 or grouping(a)=1
select case when grouping(a)=1 then '合计' else cast(a as varchar) end a,
b,
c,
sum(d),sum(e) from #t
group by a,b,c with rollup
having grouping(c)=0 or grouping(a)=1
--情况三：有多个分类汇总列，需要全部的小计和合计。
select case when grouping(a)=1 then '合计' else cast(a as varchar) end a,
case when grouping(b)=1 and grouping(a)=0 then '小计' else cast(b as varchar) end b,
case when grouping(c)=1 and grouping(b)=0 then '小计' else cast(c as varchar) end c,
sum(d),sum(e) from #t
group by a,b,c with rollup
--另外一种显示小计的方式
select case when grouping(a)=1 then '合计'
when grouping(b)=1 then cast(a as varchar)+'小计'
else cast(a as varchar) end a,
case when grouping(b)=0 and grouping(c)=1
then cast(b as varchar)+'小计' else cast(b as varchar) end b,
case when grouping(c)=1 and grouping(b)=0
then '' else cast(c as varchar) end c,
sum(d),sum(e) from #t
group by a,b,c with rollup
--情况四：有多个分类汇总列，需要部分的小计和合计
select case when grouping(a)=1 then '合计' else cast(a as varchar) end a,
b,
case when grouping(c)=1 and grouping(b)=0 then '小计' else cast(c as varchar) end c,
sum(d),sum(e) from #t
group by a,b,c with rollup
having grouping(a)=1 or grouping(b)=0
select case when grouping(a)=1 then '合计' else cast(a as varchar) end a,
case when grouping(b)=1 and grouping(a)=0 then '小计' else cast(b as varchar) end b,
c,
sum(d),sum(e) from #t
group by a,b,c with rollup
having grouping(a)=1 or grouping(b)=1 or grouping(c)=0
