mysql> SELECT avg(UnitPrice)
    -> FROM order_details;
+----------------+
| avg(UnitPrice) |
+----------------+
|    26.21851972 | 
+----------------+
1 row in set (0.01 sec)

mysql> SELECT FORMAT(avg(UnitPrice),2) AS 'Przecietna cena'
    -> FROM order_details;
+-----------------+
| Przecietna cena |
+-----------------+
| 26.22           | 
+-----------------+
1 row in set (0.35 sec)
