Re: select with date_part and month failure....

am  18.04.2006, um  9:20:50 +0200 mailte P.MO folgendes:
>
>
> Hello
>
> I have the same problem against various PostgreSQL 8.1.3, 8.0.2 and 7.4.7:
>
> I have a table containing periodical invoices. it contain's the last time the
> invoce was printed and a period in month to be waited before next time.
> My querry works with date_parts on days but never with months:
>
> create temp table tstdates (
>  lasttimedone date,
>  period integer
> );
>
> insert into tstdates values ('2006-01-01',2);
> insert into tstdates values ('2006-02-01',2);
> insert into tstdates values ('2006-03-01',2);
> insert into tstdates values ('2006-04-01',2);
>
> -- doesn' t works :
> select * from tstdates where
> date_part('month',now()-lasttimedone) >= period;

now()-lasttimedone returns the number of days, not the months.

You can use this:

test=# select * from tstdates where date_part('month',age(lasttimedone)) >= period;
 lasttimedone | period
--------------+--------
 2006-01-01   |      2
 2006-02-01   |      2
(2 rows)


HTH, Andreas
--
Andreas Kretschmer    (Kontakt: siehe Header)
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