Beispiele aus den Uebungen, die auf der Datenbank "fastfood" ausgefuehrt wurden.

Tip: verifiziert diese Ausgaben mit Hilfe von Pivot-Tabellen, um so den Zusammenhang
zwischen group-by-Statements und Pivot-Tabellen zu sehen.

-----

mysql> select city, sum(amount) from Umsaetze where location ="Autobahn" group by city;
+-------------+-------------+
| city        | sum(amount) |
+-------------+-------------+
| Duesseldorf |      798014 |
| Koeln       |      825731 |
+-------------+-------------+
2 rows in set (0.17 sec)

mysql> select branch, city, sum(amount) from Umsaetze where location ="Autobahn" group by branch, city;  
+--------------+-------------+-------------+
| branch       | city        | sum(amount) |
+--------------+-------------+-------------+
| Mc Doof      | Duesseldorf |      395778 |
| Mc Doof      | Koeln       |      422209 |
| Wuerger King | Duesseldorf |      402236 |
| Wuerger King | Koeln       |      403522 |
+--------------+-------------+-------------+
4 rows in set (0.19 sec)

mysql> select branch, city, sum(amount) from Umsaetze where location = "Autobahn" group by branch, city having sum(amount)> 400000;
+--------------+-------------+-------------+
| branch       | city        | sum(amount) |
+--------------+-------------+-------------+
| Mc Doof      | Koeln       |      422209 |
| Wuerger King | Duesseldorf |      402236 |
| Wuerger King | Koeln       |      403522 |
+--------------+-------------+-------------+

mysql> select city, branch, count(amount) from Umsaetze where year = 2004 group by city, branch; 
+-------------+--------------+---------------+
| city        | branch       | count(amount) |
+-------------+--------------+---------------+
| Duesseldorf | Mc Doof      |          1814 |
| Duesseldorf | Wuerger King |          1767 |
| Koeln       | Mc Doof      |          1827 |
| Koeln       | Wuerger King |          1830 |
+-------------+--------------+---------------+
4 rows in set (0.15 sec)

mysql> select city, branch, location, count(amount) from Umsaetze where year = 2004 group by city, branch, location; 
+-------------+--------------+-----------------+---------------+
| city        | branch       | location        | count(amount) |
+-------------+--------------+-----------------+---------------+
| Duesseldorf | Mc Doof      | Autobahn        |           437 |
| Duesseldorf | Mc Doof      | Einkaufszentrum |           474 |
| Duesseldorf | Mc Doof      | Innenstadt      |           451 |
| Duesseldorf | Mc Doof      | Rheinufer       |           452 |
| Duesseldorf | Wuerger King | Autobahn        |           429 |
| Duesseldorf | Wuerger King | Einkaufszentrum |           439 |
| Duesseldorf | Wuerger King | Innenstadt      |           426 |
| Duesseldorf | Wuerger King | Rheinufer       |           473 |
| Koeln       | Mc Doof      | Autobahn        |           491 |
| Koeln       | Mc Doof      | Einkaufszentrum |           447 |
| Koeln       | Mc Doof      | Innenstadt      |           432 |
| Koeln       | Mc Doof      | Rheinufer       |           457 |
| Koeln       | Wuerger King | Autobahn        |           461 |
| Koeln       | Wuerger King | Einkaufszentrum |           470 |
| Koeln       | Wuerger King | Innenstadt      |           460 |
| Koeln       | Wuerger King | Rheinufer       |           439 |
+-------------+--------------+-----------------+---------------+
16 rows in set (0.17 sec)