PrestaShop/PrestaShop — pull request #780 by MyBB-Services (2013-10-02 08:35:36+00:00)
Title: [*] BO : Allow complex GROUP BY in SQL Manager

Improved slightly the RequestSql class to allow GROUP BY to use some functions.

For example, this would not work on the current version :
```sql
SELECT
DATE_FORMAT(`date_add`, '%m/%Y') as Mois,
SUM(shipping_cost_tax_excl) as `Frais de port HT`,
SUM(shipping_cost_tax_incl) as `Frais de port TTC`
FROM ps_order_carrier
GROUP BY MONTH(ps_order_carrier.date_add)
```
The GROUP BY MONTH(date_add) being the issue. This PR fixes it.