SELECT ISNULL(NULLIF(DATABASE_COLUMN,''),' ')
SELECT ISNULL(DATABASE_COLUMN,' ')NULLIF returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression and if first expression is empty/blank then NULLIF returns a null value of the type of the first expression.
So that’s it. Enjoy your life.