Created attachment 41775 [details] [review]
Bug 14704 - members/statistics.pl crashes because the SQL 'return'-keyword might be reserved at 'return FROM ('

I got the following if I execute directly the second query in my MariaDB CLI:

ERROR 1054 (42S22): Unknown column 'tmp.return' in 'field list'

(In reply to Jonathan Druart from comment #2)
> I got the following if I execute directly the second query in my MariaDB CLI:
> 
> ERROR 1054 (42S22): Unknown column 'tmp.return' in 'field list'

That is because my hastily created example SQL was missing explicit definition for issues.return and old_issues.return.
This wasn't the case in the code (hopefully).

Try this:

SELECT COUNT(*) as count_precedent_state,tmp.issues,tmp.onloan,tmp.return
FROM (
    SELECT it.*, i.return FROM issues i, items it
    WHERE i.borrowernumber = 1234 AND
          i.itemnumber = it.itemnumber AND
          DATE(i.issuedate) < CAST(now() AS date)
    UNION
    SELECT it.*, oi.return FROM old_issues oi, items it
    WHERE oi.borrowernumber = 1234 AND
          oi.itemnumber = it.itemnumber AND
          DATE(oi.issuedate) < CAST(now() AS date) AND
          DATE(oi.returndate) = CAST(now() AS date)
    ) tmp
GROUP BY tmp.issues,tmp.onloan,tmp.return;

The dynamically created SQL here is problematic and needs to be overhauled on a more broader level. Since the columns desired can be gained from a syspref, the SQL needs to take that into account as well. This is an optimal scenario to leverage DBIx and its more configurable search building.