检查mysql数据库PHP中的N / A值

Question

My database record contains column which is N/A value which is null.

But when I retrieve them from mysql database. It shows me N/A value which I don't want to see. I did a check for that ,but no luck, the checking condition is fail

I used

empty()
is_null()
$my_variable == null
$my_variable == " "

but the check still fail. Any know how to use PHP to check the value that retrieved from the database?

updated ques: Name Type Collation Attributes Null Default Extra Actio

 4  description text    latin1_swedish_ci       No  None

default is none

Answer 1

I changed it to default NULL and the field can be NULL, then right now I can check for null value.