IN Operator SQL

Question

I have a table called NUMS with a single column n.
And I fill values 1,2,3,4,5,null in it.

Now a query

SELECT n FROM Nums 
 WHERE n IN (1, 2,         


        

Answer 1

 SELECT n FROM Nums  
 WHERE n IN (1, 2)
  Or n Is null

This will retrieve what you intend to get. As said by Mitch normally a comparison to Null yields UNKNOWN. This is because NULL itself is defined as an undefined value. It's like saying I lived in Nottingham, Birmingham and somewhere. Finding somewhere on the world map can prove a bit tricky as it is undefined.