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* using a list to query
@ 2009-05-02 16:55 johnf <jfabiani@yolo.com>
2009-05-03 01:34 ` Re: using a list to query Craig Ringer <craig@postnewspapers.com.au>
0 siblings, 1 reply; 3+ messages in thread
From: johnf @ 2009-05-02 16:55 UTC (permalink / raw)
To: pgsql-sql
I have a list (or array) of primary keys stored in a field (data type text).
I would like to use the list to retrieve all the data from a table based on
the list.
my text field contains:
'123,134,343,345'
I would to do something like the following:
Select * from table1 where table1.pkid in (select myTextfield from table2)
So the question is there a simple way to use the list to retrieve my data?
--
John Fabiani
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: using a list to query
2009-05-02 16:55 using a list to query johnf <jfabiani@yolo.com>
@ 2009-05-03 01:34 ` Craig Ringer <craig@postnewspapers.com.au>
2009-05-03 22:26 ` Re: using a list to query johnf <jfabiani@yolo.com>
0 siblings, 1 reply; 3+ messages in thread
From: Craig Ringer @ 2009-05-03 01:34 UTC (permalink / raw)
To: johnf <jfabiani@yolo.com>; +Cc: pgsql-sql
johnf wrote:
> I have a list (or array) of primary keys stored in a field (data type text).
> I would like to use the list to retrieve all the data from a table based on
> the list.
>
> my text field contains:
> '123,134,343,345'
>
> I would to do something like the following:
>
> Select * from table1 where table1.pkid in (select myTextfield from table2)
>
> So the question is there a simple way to use the list to retrieve my data?
http://www.postgresql.org/docs/8.3/static/functions-matching.html
SELECT * FROM table1
WHERE table1.pkid IN (
SELECT x FROM regexp_split_to_table(myTextfield, ',') AS x
);
... but you should consider storing your list in an array instead, or
using a more conventional child table with a (pkid, refid) pair list.
--
Craig Ringer
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: using a list to query
2009-05-02 16:55 using a list to query johnf <jfabiani@yolo.com>
2009-05-03 01:34 ` Re: using a list to query Craig Ringer <craig@postnewspapers.com.au>
@ 2009-05-03 22:26 ` johnf <jfabiani@yolo.com>
0 siblings, 0 replies; 3+ messages in thread
From: johnf @ 2009-05-03 22:26 UTC (permalink / raw)
To: pgsql-sql
On Saturday 02 May 2009 06:34:57 pm Craig Ringer wrote:
> johnf wrote:
> > I have a list (or array) of primary keys stored in a field (data type
> > text). I would like to use the list to retrieve all the data from a table
> > based on the list.
> >
> > my text field contains:
> > '123,134,343,345'
> >
> > I would to do something like the following:
> >
> > Select * from table1 where table1.pkid in (select myTextfield from
> > table2)
> >
> > So the question is there a simple way to use the list to retrieve my
> > data?
>
> http://www.postgresql.org/docs/8.3/static/functions-matching.html
>
> SELECT * FROM table1
> WHERE table1.pkid IN (
> SELECT x FROM regexp_split_to_table(myTextfield, ',') AS x
> );
>
> ... but you should consider storing your list in an array instead, or
> using a more conventional child table with a (pkid, refid) pair list.
>
> --
> Craig Ringer
Thanks - I think this will work very well. I considered an array but at the
moment I don't have an easy way of retrieving data from an array. I'm
working on that as I type. The other solution would be a table but that
seems over kill for one field.
Thanks again
--
John Fabiani
^ permalink raw reply [nested|flat] 3+ messages in thread
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2009-05-02 16:55 using a list to query johnf <jfabiani@yolo.com>
2009-05-03 01:34 ` Craig Ringer <craig@postnewspapers.com.au>
2009-05-03 22:26 ` johnf <jfabiani@yolo.com>
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