SQL语句求助！两个表的count值相除

[w521286]

表一：tab1
字段：id,name,sex...

表二：tab2
字段：id,name,sex...

要求：用一条sql查询出表一中name为 “xx”的人数占表二中name为 “xx” 的人数的百分比

(select count(id) from tab1 where name="xx")/(select count(id) from tab2 where name="xx")

这样好像不行啊

[AcHerat]

select
(select count(id) from tab1 where name="xx")/(select count(id) from tab2 where name="xx")

??? 除数要判断是否为0。。。

[geniuswjt]

select  
(select count(id) from tab1 where name='xx')/
nullif((select count(id) from tab2 where name='xx'),0)

[rucypli]

[Quote=引用 2 楼 geniuswjt 的回复:]
SQL code

select
(select count(id) from tab1 where name='xx')/
nullif((select count(id) from tab2 where name='xx'),0)
[/Quote]1

[snbxp]

select (select count(1)*1.0 from tb1 where name='xx')/(select count(1) from tb2 where name='xx')

[勿勿]

CREATE TABLE [dbo].[tb](
	[id] [int] NULL,
	[code] [decimal](18, 2) NULL
) ON [PRIMARY]

GO

INSERT INTO [DBText].[dbo].[tb]
           ([id]
           ,[code])
     VALUES
           (<id, int,>
           ,<code, decimal(18,2),>)
GO



CREATE TABLE [dbo].[tbs](
	[id] [int] NULL,
	[path] [varchar](100) NULL
) ON [PRIMARY]

GO

INSERT INTO [DBText].[dbo].[tbs]
           ([id]
           ,[path])
     VALUES
           (<id, int,>
           ,<path, varchar(100),>)
GO



select  
 cast(cast((
(  (select cast( COUNT(*)  as decimal(18, 4)) from tbs) /nullif((select cast(COUNT(*)as decimal(18, 4)) from tb ),0))  
 
 *100) as decimal(18, 2)) as varchar(50))   +'%'
as 个数百分比  


个数百分比
---------------------------------------------------
14.29%

(1 行受影响)

[dawugui]

select cast(
       (select count(id) from tab1 where name="xx")*100.0
       /
       (select count(id) from tab2 where name="xx")
       as decimal(18,2))

[w521286]

谢谢各位