checking null value

Hi all,
I know someone answered this in the past but couldn't find the post.
How do I check for nulls if they might be in the column? colb and colc might
have null value?
the below query returns some rows that don't contain value "blue" which is
wrong.
select cola,colb,colc from tableA where
cola = 'blue' or
colb = 'blue' or
colc = 'blue'
thanks
gv>> How do I check for nulls if they might be in the column? colb and colc
Nulls can be checked using IS [NOT] NULL clause in SQL.
Since you are using OR operator, the query might return every row where any
one of cola, colb, col3 or any combination of the three has a value 'blue'.
Based on the query you posted, the result you see is valid.
Anith