Say I have a table titles like this:
id (INT) | title (VARCHAR)
-----------------------------
1 | Some title
2 | Another title
3 | Yep another
I accidentally discovered if I use the query:
SELECT * FROM `titles` WHERE `id` = '1,2,3'
Mysql returns me the row with id = 1
Maybe I missed this whilst learning about Mysql. Is this something that's been supported across many version of Mysql?
Since id is a numeric column, mysql silently converts the string '1,2,3' to a number. During the conversion mysql stops at the first character that cannot be interpreted as part of a number, in this particular case the comma after the 1. So, only the character 1 will be used during the conversion.
mysql> select 1 = "1,2,3";
+-------------+
| 1 = "1,2,3" |
+-------------+
| 1 |
+-------------+
1 row in set, 1 warning (0.00 sec)
mysql> select 1 = ",1,2,3"; -- <- does not start with a number
+--------------+
| 1 = ",1,2,3" |
+--------------+
| 0 |
+--------------+
1 row in set, 1 warning (0.00 sec)
