Some rows in some columns in a table contain null. When I SELECT them with
LIKE clause on those columns, rows that contain null, not be selected. How
to solve it?

Table X

Column1 Column2
===============
AAA NULL
AAB AAB
AAC AAC

SELECT * FROM X WHERE COLUMN2 LIKE '%'

The result are:

Column1 Column2
===============
AAB AAB
AAC AAC