Question

I wish to do something like this:

DECLARE @IgnoreNulls = 1;

SELECT Col1, Col2
FROM tblSimpleTable
IF @IgnoreNulls
BEGIN
  WHERE Col2 IS NOT NULL
END
ORDER BY Col1 DESC;

The idea is to, in a very PHP/ASP.NET-ish kinda way, only filter NULLs if the user wishes to. Is this possible in T-SQL? Or do we need one large IF block like so:

IF @IgnoreNulls
BEGIN
  SELECT Col1, Col2
  FROM tblSimpleTable
  WHERE Col2 IS NOT NULL
  ORDER BY Col1 DESC;
END
ELSE
BEGIN
  SELECT Col1, Col2
  FROM tblSimpleTable
  ORDER BY Col1 DESC;
END

Answer 1

You can do that this way:

SELECT Col1, Col2
FROM tblSimpleTable
WHERE ( @IgnoreNulls != 1 OR Col2 IS NOT NULL )
ORDER BY Col1 DESC