Question

I want to update a record in database if a condition exists .

set nocount off;

if exists ( select * from ParentTable where ID=@ParentID )
  update ChildTable set Title=@Title,ParentID=@ParentID where ID=@ID;
else return -2;

but it returns -1 if the ParentID doesn’t exists .

I’m using ExecuteNonQuery() to run this procedure

Answer 1

The return value of ExecuteNonQuery is the number of rows affected, not a custom return code. While -1 (the current return value) seems like a suitable replacement in this particular case, to solve the more general case you’ll have to use ExecuteScalar and use the pattern below:

declare @retval int

if exists ( select * from ParentTable where ID=@ParentID )
begin
    update ChildTable set Title=@Title,ParentID=@ParentID where ID=@ID;
    select @retval = @@ROWCOUNT
end
else 
    select @retval = -1

select @retval