if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_getcharcount]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[f_getcharcount]
GO

--得到一個字符串在另一個字符串中出現的次數
create function f_getcharcount(
@str varchar(8000),
@chr varchar(20)
) returns int
as
begin
declare @re int,@i int
select @re=0,@i=charindex(@chr,@str)+1
while @i>1
	select @re=@re+1
		,@str=substring(@str,@i,8000)
		,@i=charindex(@chr,@str)+1
return(@re)
end
go

--調用示例
select dbo.f_getcharcount('aadddbbbbad','ad')