Using WHERE clause with BETWEEN and null date parameters

Question

One of my WHERE clauses is the following:

AND (DateCreated BETWEEN @DateFrom and @DateTo OR (@DateFrom IS NULL OR @DateTo IS NULL))

Answer 1

Use this where clause

WHERE  ( DateCreated BETWEEN @DateFrom AND @DateTo )
        OR ( @DateFrom IS NULL
             AND @DateTo IS NULL )
        OR ( @DateFrom IS NULL
             AND DateCreated <= @DateTo )
        OR ( @DateTo IS NULL
             AND DateCreated >= @DateFrom )