请问一sql count

请教一sql count
type inum
1 2
2 3
3 5
1 4
2 8
3 11

select count(*) from 表 group by type

type count
1 6
2 11
3 16

现在想要把类型1，2的合并count
type count
1和2 17
3 16

该如何写

------解决方案--------------------
select sum(inum) from tt group by (type-1)/2

------解决方案--------------------

SQL code

select type,SUM(num)num from (
select case TYPE when 2 then '1'+'和2' when 1 then '1'+'和2' else '3' end type,num from tb)a group by type
/*
type    num
1和2    17
3    16
*/

------解决方案--------------------

SQL code


use tempdb 
go
create table tb (type int ,num int)
go
insert tb 
select 1, 2 union all
select 2 ,3 union all
select 3 ,5 union all
select 1 ,4 union all
select 2 ,8 union all
select 3 ,11

select type ,sum(num) as num from (select case when type=1 then '1和2' when type=2 then '1和2' else '3' end type, sum(num) as num  from tb group by type)a group by type

type num
---- -----------
1和2  17
3    16

(2 行受影响)

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