Switch Case in T-SQL In where Clause

Hello Ex开发者_如何学Pythonperts i have A Sp , which Contains lot of if/else Condition Please help me how to use Switch Case in T-SQL In where Clause. here is my Query

if (@Form ='page.aspx')
begin
select 
    DT.Column,DST.Column1,
    DST.Code  from Table DT
join Table2 DST 
    on DT.ID= DST.ID
where 
    DT.code = 'XX1'
    and DT.CDID = @cdid
end

 if (@Form ='Page2.aspx')
begin
select 
    DT.Column,DST.Column1,
    DST.Code  from Table DT
join Table2 DST 
    on DT.ID= DST.ID
where 
    DT.code = 'XX2'
    and DT.CDID = @cdid
end

Please Help me, Any pointer or suggestion would be really helpful thanks

For this particular query you could write

select

        DT.Column,DST.Column1,
        DST.Code  from Table DT

  join Table2 DST 

        on DT.ID= DST.ID
  where 

              DT.code = case @Form when 'page.aspx' then 'XX1' else 'XX2' end
 and DT.CDID = @cdid

declare @dtCode varchar(255)
select @dtCode = 
   CASE @Form 
      WHEN 'page.aspx' then 'XX1' 
      WHEN 'page2.aspx' then 'XX2' 
      ELSE 'NoIdea'
   END

select
    DT.Column,DST.Column1,
    DST.Code  from Table DT
join Table2 DST 
    on DT.ID= DST.ID
where 
    DT.code = @dtCode
    and DT.CDID = @cdid

Note: I have written this with help of notepad & not used Query Analyzer to check for any syntax errror. But, I hope you get the idea (to not repeat the SQL statements when the only thing that changes is the value of dtCode).