Wenn SQLite immer ein Gruppierungsfeld haben will, dann geben wir es ihm halt
SQL-Code:
SELECT
1 as Feld, AVG(s.tmp) as tmp
FROM
(
SELECT
table1.feld3, table2.feld5, (SUM(...)/COUNT(*))/10 AS tmp
FROM table1
JOIN table2 ON table1.fkey = table2.pkey
GROUP BY
table1.feld3, table2.feld5
) s
group by
s.Feld;