[Mondrian] Parenthesized queries in UNION

[Tiago Ferreira]

I put the parenthesis because MySQL wasn't accepting the order by in the
first select. It was far from a good solution but seemed slightly better
than before and allowed to test for more issues on multiple measure groups.

Meanwhile I made it output only one order by for the whole union as you
suggest. Before it was not just generating an order by for each select, but
the last one would have two, both by column name and by ordinal. Now it
only does the ordinal order for unions

It's one of the commits in the last pull request I made:

https://github.com/webdetails/mondrian/commit/e37cc17f6a112da3639e5591c5a7de193c368766

>From what I tested it runs ok in MySQL, Hypersonic and Oracle.

On 4 December 2012 07:04, Julian Hyde <jhyde at pentaho.com> wrote:

> By the way, this was the commit:
> https://github.com/pentaho/mondrian/commit/8837434cc059a0023da25288abfe5e9ec21f38fc
> .
>
> Julian
>
> On Dec 3, 2012, at 10:44 PM, Julian Hyde <jhyde at pentaho.com> wrote:
>
> > Tiago,
> >
> > What was the error that made you make the following change, and on what
> database?
> >
> > Before your change, the code used to generate
> >
> > SELECT ... ORDER BY UNION SELECT ... ORDER BY
> >
> > and after your change generates
> >
> > (SELECT ... ORDER BY) UNION (SELECT ... ORDER BY)
> >
> > ORDER BY inside a subquery is illegal per the SQL standard (and as it
> happens makes MongoDB's parser barf), so I wonder if that was the real
> problem you were facing. I am fixing it to generate
> >
> >  (SELECT ...) UNION (SELECT ...) ORDER BY
> >
> > and, since simpler is better, I wonder if I could go one step further
> and generate
> >
> >  SELECT ... UNION SELECT ... ORDER BY
> >
> > To help me decide, it would help to know why you added the parentheses
> in the first place.
> >
> > Julian
> > _______________________________________________
> > Mondrian mailing list
> > Mondrian at pentaho.org
> > http://lists.pentaho.org/mailman/listinfo/mondrian
>
>


-- 
Tiago G.F.
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