Hi, while trying to upgrade to latest HEAD I'm getting this under PG:
ERROR: column "a.course" must appear in the GROUP BY clause or be used in an aggregate function
SELECT COUNT('x') FROM mdl_assignment_submissions s JOIN mdl_assignment a ON a.id = s.assignment JOIN mdl_modules m ON m.name = 'assignment' JOIN mdl_course_modules cm ON (cm.module = m.id AND cm.instance = a.id) ORDER BY a.course, s.assignment
Also, under MSSQL I get some errors.
Attaching patch that should fix the problem, by splitting the $sqlfrom into two components and not using it in the COUNT statement.
Important note: Both forum and glossary exhibit the same problem.