I have a single table which I would like to search on a unique column
varchar(15) that may have some nulls. Employee social club member no,
some employees have a number and others don't. Those that do have a number
will all have a unique number.

I had added an index using:
ALTER TABLE employees ADD INDEX(emp_socialclubno);

However when I run:
mysql> explain select employeeid from employees where
emp_socialclubno=103833988;
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
+----+-------------+------------+------+---------------+------+---------+------+--------+-------------+
1 row in set (0.00 sec)

So this indicates that even though the emp_socialclubno column has an index
it is not being used when this column is searched ?

Is this right or am I missing something ?

Thanks in advance...

McMurphy wrote:

looks like your query is for table employees but the explain is run on
properties. these are two different tables!!!