Inserts and Updates in SQL Server for a stored procedure

Question

I have a table like this in SQL Server:

varID(PK)    dataID(PK)  is_used
A            1           0
B            1           0

Then I'm loading data to update is_used to 1 if the varID/dataID combo exists and add it in otherwise.

So I have to insert/update these varID/dataID combos.

varID(PK)    dataID(PK)  
B            1           
C            1

So the updated table would look like this:

varID(PK)    dataID(PK)  is_used
A            1           0
B            1           1
C            1           1

What's the easiest way to do this? I will do it in a stored procedure.

Answer 1

Procedure tries to update is_used given a key. If unsuccessful, inserts new row. Note I put 0 as default value for is_used - I think is_used = 1 for (C, 1) is an inadvertence.

create proc AddVarDataCombo (@varID varchar(100), @dataID int)
as
   set nocount on

   update ATable
      set is_used = 1
    where varID = @varID
      and dataID = @dataID

   if @@rowcount = 0
   begin
      insert into ATable 
           values (@varID, @dataID, 0)
   end