mysql where exact match

Question

When i write this query

SELECT cd.title, cd.city FROM coupon_detail cd WHERE cd.id = 260;

return

title            city  
--         


        

Answer 1

Well, you should not use quote if the id is INT. The way MySQL does is if you use String to compare a INT, it uses just the valid initial integer from start.

see this:

mysql> desc coupon_detail;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| id    | int(11)      | YES  |     | NULL    |       |
| title | varchar(100) | YES  |     | NULL    |       |
| city  | varchar(100) | YES  |     | NULL    |       |
+-------+--------------+------+-----+---------+-------+
3 rows in set (0.04 sec)

mysql> SELECT cd.title, cd.city FROM coupon_detail cd WHERE cd.id = 'ff260';
Empty set, 1 warning (0.00 sec)

mysql> SELECT cd.title, cd.city FROM coupon_detail cd WHERE cd.id = '260ff';
+-----------------+--------+
| title           | city   |
+-----------------+--------+
| Butterfly world | Mohali |
+-----------------+--------+
1 row in set, 1 warning (0.00 sec)

mysql> SELECT cd.title, cd.city FROM coupon_detail cd WHERE cd.id = 260;
+-----------------+--------+
| title           | city   |
+-----------------+--------+
| Butterfly world | Mohali |
+-----------------+--------+
1 row in set (0.00 sec)

mysql> SELECT cd.title, cd.city FROM coupon_detail cd WHERE cd.id = 26011;
Empty set (0.00 sec)

The idea is not to mix numbers and aphabets to compare a INT column. If you have to you may consider

• converting ID column to VARCHAR. In that case auto-increment may go away.
• have application logic to query only the strings that has numerics.