How to convert empty spaces into null values, using SQL Server?

Question

I have a table and the columns on this table contains empty spaces for some records. Now I need to move the data to another table and replace the empty spaces with a N

Answer 1

I solved a similar problem using NULLIF function:

UPDATE table 
SET col1 = NULLIF(col1, '')

From the T-SQL reference:

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.