Difference between NULL and Blank Value in Mysql

Question

I have to check for a value of a particular Column named RESULT is blank or not.

When I check with if RESULT IS NULL, the query failed, bu

Answer 1

In tri-value logic, NULL should be used to represent "unknown" or "not applicable" An empty column should represent "known but empty".

Some DBMS products don't follow this convention all the time but I consider them deficient. Yes, you know who you are, Oracle :-)

In addition, while NULL can be put into any column type (ignoring not null clauses for now), you cannot put an "empty" value into a non-character field (like integer).