Re: logical OR on two fields in a table in a database

[Erin ONeill]

hmm that didn't help at all. Here are the two explains (for the original with the OR and for the UNION select) These were done on the dev box and not the production box:

mysql> explain SELECT Username,Email,U_Number from Users WHERE Username = '[e-mail]' OR Email = '[e-mail]';
+-----------+------+------------------+------+---------+------+-------+-------------+
| table | type | possible_keys | key | key_len | ref | rows | Extra |
+-----------+------+------------------+------+---------+------+-------+-------------+
| Users | ALL | Username,indx1 | NULL | NULL | NULL | 44857 | Using where |
+-----------+------+------------------+------+---------+------+-------+-------------+
1 row in set (0.00 sec)


mysql> explain SELECT Username,Email,U_Number from Users WHERE Username = '[e-mail]' UNION
-> SELECT Username,Email,U_Number from Users WHERE Email = '[e-mail]' ;
-----------+------+---------------+------+---------+------+-------+-----------------------------------------------------+
| table | type | possible_keys | key | key_len | ref | rows | Extra |
+-----------+------+---------------+------+---------+------+-------+-----------------------------------------------------+
| | | | | 0 | | 0 | Impossible WHERE noticed after reading const tables |
| Users | ALL | NULL | NULL | NULL | NULL | 44857 | Using where |
+-----------+------+---------------+------+---------+------+-------+-----------------------------------------------------+
2 rows in set (0.58 sec)