Question

I have a sql server 2008 table with two nullable decimal values and an ID. I am passing the values and an ID into a stored procedure. These values may be the same as the existing values, or they may be something else. If it is something else, I want to update the existing record. My question is, I’m not sure how to do this because of the nullable factor.

DECLARE @count int
SET @count=(SELECT Count(ID) FROM [MyTable] WHERE 
  [ID]=@id AND 
  [Value1]<>@value1 AND
  [Value2]<>@value2
)

IF (@count>0)
BEGIN
  UPDATE
    [MyTable]
  SET
    [Value1]=@value1,
    [Value2]=@value2
  WHERE
    [ID]=@id
END

My problem is handling the null case. Can somebody please show me how to handle the null case that I described?

Thank you!

Answer 1

Use ISNULL to provide a default value for Value1 and Value2 in your comparison.
And I think you’ll want an OR if you you want to update if either value is different.

SELECT @count = Count(ID) FROM @MyTable 
WHERE ID = @id 
   AND (ISNULL(Value1,0) <> @value1 OR ISNULL(Value2,0) <> @value2)