Re: SQL-Statement

Quoth Markus Espenhain <espenhain(at)etes(dot)de>:
> SELECT * FROM Hauptantrag WHERE (select datenfeldname from
> datenexport) > (select datum_von from datenexport) AND (select
> datenfeldname from datenexport) < (select datenexport.datum_bis from
> datenexport) limit 10;

If I understand you right, you want to compare some column from
Hauptantrag to a range of values (datum_bis < 'some column' < datum_von),
but you don't know what the column will be ahead of time.

I believe this requires a dynamic sql statement, such as the plpython
command 'execute':

rv = plpy.execute(
"SELECT * FROM Hauptantrag WHERE %s > %f AND %s < %f"
% (colname, datum_von, datum_bis),
10)

If you can, it's probably best to rework the logic of your code to
avoid having to test unknown columns.

--
colin | perfection is reached, not when there is no longer anything to add,
roald | but when there is no longer anything to take away.
(antoine de saint-exupery)