How do you get SQL to recognize WHERE column = NULL?

Question

In microsoft SQL, I have the following statement (roughly):

UPDATE sometable 
   SET somecolumn = @somevalue 
 WHERE somecolumn = NULL;

@somevalue is set previously in the script.

This runs fine and SQL tells me zero rows are affected. There are five rows were somecolumn is NULL. What am I doing wrong?

Answer 1

You have to use IS NULL instead to test for a NULL value in the column.

 UPDATE sometable SET somecolumn = @somevalue WHERE somecolumn IS NULL;