Ihr ORDER BY in der Unterabfrage der abgeleiteten Tabelle wird in MySQL 5.7 ignoriert.
Siehe https://dev.mysql.com/ doc/refman/5.7/en/derived-table-optimization.html
Ihre äußere Abfrage hat ein JOIN und ein GROUP BY, daher qualifiziert sie sich nicht für die Weitergabe von ORDER BY, daher ignoriert sie ORDER BY.
Dieses Optimiererverhalten wird durch den Optimiererschalter derived_merge gesteuert . Sie können es deaktivieren.
Demo:
mysql [localhost] {msandbox} (test) > select @@version;
+-----------+
| @@version |
+-----------+
| 5.7.21 |
+-----------+
mysql [localhost] {msandbox} (test) > SELECT columnPrimaryKey, column1, column2, column3 FROM (SELECT columnPrimaryKey, column1, column2, column3 FROM testTable ORDER BY column2 ) AS tbl GROUP BY column3;
+------------------+----------------+---------+---------+
| columnPrimaryKey | column1 | column2 | column3 |
+------------------+----------------+---------+---------+
| 1 | Some Name 8-4 | 4 | 8 |
| 6 | Some Name 9-1 | 1 | 9 |
| 8 | Some Name 10-2 | 2 | 10 |
+------------------+----------------+---------+---------+
mysql [localhost] {msandbox} (test) > set optimizer_switch = 'derived_merge=off';
Query OK, 0 rows affected (0.00 sec)
mysql [localhost] {msandbox} (test) > SELECT columnPrimaryKey, column1, column2, column3 FROM (SELECT columnPrimaryKey, column1, column2, column3 FROM testTable ORDER BY column2 ) AS tbl GROUP BY column3;
+------------------+----------------+---------+---------+
| columnPrimaryKey | column1 | column2 | column3 |
+------------------+----------------+---------+---------+
| 5 | Some Name 8-1 | 1 | 8 |
| 6 | Some Name 9-1 | 1 | 9 |
| 8 | Some Name 10-2 | 2 | 10 |
+------------------+----------------+---------+---------+
