有点复杂的字符串处理

Question

SQL语句怎么写
y2-0.75-4
y2-0.55-2(660v)
y-132m-0.37-6要求：如果有括号就去除括号与括号中的内容，如果有3个“-”就去除前两个“-”中的内容与其中一个“-”
变成y2-0.75-4
y2-0.55-2
y2-0.37-6

Answer 1

;with TT
as(select 'y2-0.75-4' as num union 
select 'y2-0.55-2(660v)' union
select 'y-132m-0.37-6')select case when CHARINDEX( '(',num) >0 
then LEFT(num,charindex('(',num) - 1) 
else 
case when LEN(num) - len(REPLACE(num,'-',''))=3
then 
LEFT(num,charindex('-',num))+substring(SUBSTRING(num,charindex('-',num)+1,LEN(num)),charindex('-',SUBSTRING(num,charindex('-',num)+1,LEN(num)))+1,LEN(SUBSTRING(num,charindex('-',num)+1,LEN(num))))
else 
num
end 
end
from TT/*
y-0.37-6
y2-0.55-2
y2-0.75-4*/

Answer 2

--創建函數
create  function f_firstposition(@Str varchar(8000),@StrSep varchar(10),@AppPos int)
returns int
begin
    declare @i int
    declare @ii int
    set @Str=rtrim(ltrim(@Str))
    set @i=1
    select @ii=charindex(@StrSep,@Str)
    if @i=@AppPos
        return @ii
    else
    while @AppPos>@i
    begin
        if charindex(@StrSep,right(@Str,len(@Str)-@ii))<>0
                select @ii=charindex(@StrSep,right(@Str,len(@Str)-@ii))+@ii
        else
                set @ii=0
        set @i=@i+1
    end    return @ii
END
go;--執行查詢
WITH a1 (cstr) AS
(
SELECT 'y2-0.75-4' UNION ALL
SELECT 'y2-0.55-2(660v)' UNION ALL
SELECT 'y2-132m-0.37-6'
)
,a2 AS
(
SELECT 
CASE 
WHEN dbo.f_firstposition(cstr,'-',3)>0
THEN STUFF(cstr,dbo.f_firstposition(cstr,'-',1)+1,dbo.f_firstposition(cstr,'-',2)-dbo.f_firstposition(cstr,'-',1),'')
ELSE cstr
END cstr
FROM a1
)
SELECT
CASE 
WHEN dbo.f_firstposition(cstr,'(',1)>0
THEN STUFF(cstr,dbo.f_firstposition(cstr,'(',1),dbo.f_firstposition(cstr,')',1)-dbo.f_firstposition(cstr,'(',1)+1,'')
ELSE cstr
END cstr
FROM a2