IS NULL vs = NULL in where clause + SQL Server

Question

How to check a value IS NULL [or] = @param (where @param is null)

Ex:

Select column1 from Table1
where column2 IS NULL => works fine

If I want to replace comparing value (IS NULL) with @param. How can this be done

Select column1 from Table1
where column2 = @param => this works fine until @param got some value in it and if is null never finds a record.

How can this achieve?

Answer 1

select column1 from Table1
  where (@param is null and column2 is null)
     or (column2 = @param)

Answer 2

I realize this is an old question, but I had the same one, and came up with another (shorter) answer. Note: this may only work for MS SQL Server, which supports ISNULL(expr,replacement).

SELECT column1 FROM table1
WHERE ISNULL(column2,'') = ISNULL(@param,'')

This also assumes you treat NULL and empty strings the same way.