Does NULL have a data type?

Question

I ran into code similar to this today.

SELECT AuditDomain, 
    ObjectId,
    AuditSubdomain = CONVERT(VARCHAR(50), NULL),
    SubDomainObjectId = CONVERT(IN         


        

Answer 1

Of couse NULL has data type. Try next code to confirm:

SELECT 
  CAST(NULL AS date) AS c1,
  CAST(NULL AS time) AS c2
INTO #x;
EXEC tempdb..sp_columns '#x';

And i think that there is bug in SQL_VARIANT implementation because it lossing information about NULL type. Too bad!