Nulls and the MERGE statement: I need to set a value to infinity. How?

Question

In SQL Server 2008, I\'m using MERGE. Everything is fine except that I have 2 nullable columns. If I pass a null value and the target isn\'t null, MERGE doesn\'t see a diffe

Answer 1

This works as well and may be better when you have multiple columns that you want to check if they are different.

  MERGE @t2 a

  using @t1 b

  ON a.PK = b.PK

  WHEN MATCHED AND CHECKSUM(a.PK,a.VALUE)!= CHECKSUM(b.pk,b.VALUE)

  THEN UPDATE SET a.VALUE = b.VALUE;