Question

I have an entity attribute model for storing information related to users. I am also then trying to sort a particular entity which only contains numbers in decreasing order. I am running a query such as the following:

SELECT * FROM `user_meta` WHERE `key` = 'children'   ORDER BY `user_meta`.`value`  DESC

I had not run into problems with this query until recently when a user had 11 children and now the results look as follows

+-----+----------+-------+
| uid | key      | value |
+-----+----------+-------+
|  1  | children | 5     |
|  1  | children | 3     |
|  1  | children | 3     |
|  1  | children | 2     |
|  1  | children | 11    |
|  1  | children | 1     |
+-----+----------+-------+

I have tried various different modifications of this query but have not found anything fixing this ranking problem where 5 > 11. It might be of use but both the key and value attributes are varchar(250) if that affects the sorting algorithm that MySQL uses.

Answer 1

This happens when your column is a CHAR type. It compares the strings rather than the numbers.

You could cast it when ordering:

ORDER BY CAST(`user_meta`.`value` AS UNSIGNED)

Or for signed integers:

ORDER BY CAST(`user_meta`.`value` AS SIGNED)

See also: Cast Functions and Operators