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

here's a regex one for ya.

update table
set col1=null
where col1 not like '%[a-z,0-9]%'

essentially finds any columns that dont have letters or numbers in them and sets it to null. might have to update if you have columns with just special characters.