SQL do inner join if condition met

Question

i want a good way to improve my sql code, i have to use inner join when condition is met. I am currently replicates the code:

@SystemMerge bit

if (@SystemMe         


        

Answer 1

How about dynamic sql?

declare @sel varchar(max)

set @sel = ' SELECT
         .......
         FROM myTable
         INNER JOIN table ON table.param1=myTable.param1
        '

 if (@SystemMerge=1)  
   begin
     set @sel = @sel+'INNER JOIN systemTable on systemTable.param2=myTable.param2'
   end

exec(@sel)