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Getting one row for each subquery row...?
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* Getting one row for each subquery row...?
@ 2003-06-20 05:12 Együd Csaba <csegyud@freemail.hu>
  2003-06-20 06:07 ` Re: Getting one row for each subquery row...? Tomasz Myrta <jasiek@klaster.net>
  2003-06-20 06:11 ` Re: Getting one row for each subquery row...? Tomasz Myrta <jasiek@klaster.net>
  0 siblings, 2 replies; 4+ messages in thread

From: Együd Csaba @ 2003-06-20 05:12 UTC (permalink / raw)
  To: pgsql-sql

Hi All,
 here are my three tables. I wold like to list them in the following way: I
 need all the columns from t_stockchanges, and one field for the
productgroup
 the t_stockchanges.productid belongs to.

 But one product can belong to many groups, so i would need one row for each
 group for each product.

 My bad query is:
 ------------------------
 DB=# select t_stockchanges.productid, (select name from t_productgroups
 where id=(select productgroupid from t_prod_in_pgr where
 productid=t_stockchanges.productid)) as pgroup from t_stockchanges;
 ERROR:  More than one tuple returned by a subselect used as an expression.
 DB=#
 ---------------
 Yes, this is absolutelly true, but I would like postgres to give me all the
 tuples found. How can I ask him to do so?

 Thank you,
 -- Csaba

 ---------------------------------------------------------------------------
-
 ----------------------------------------------------
                              Table "public.t_stockchanges"
     Column     |       Type       |                      Modifiers
 ---------------+------------------+----------------------------------------
-
 ------------
  id            | integer          | not null
  stockid       | integer          | not null
  productid     | integer          | not null
  changeid      | integer          | not null
  quantity      | double precision | not null
  date          | character(19)    | not null
  purchaseprice | double precision | not null
  correction    | double precision | not null
  userid        | integer          | not null
  time          | character(19)    | default to_char(now(), 'YYYY.mm.dd
 hh:mi:ss'::text)
  prooftype     | character(10)    | not null default ''
  proofid       | integer          | default 0
 Indexes: t_stockchanges_pkey primary key btree (id),
          t_stockchanges_date btree (date),
          t_stockchanges_productid btree (productid)
 ---------------------------------------------------------------------------
-
 ----------------------------------------------------

          Table "public.t_productgroups"
    Column    |         Type          | Modifiers
 -------------+-----------------------+-----------
  id          | integer               | not null
  name        | character varying(30) | not null
  description | character varying     |
  root        | boolean               |
 Indexes: t_productgroups_pkey primary key btree (id)
 ---------------------------------------------------------------------------
-
 ----------------------------------------------------

      Table "public.t_prod_in_pgr"
      Column     |  Type   | Modifiers
 ----------------+---------+-----------
  productgroupid | integer | not null
  productid      | integer | not null
 ---------------------------------------------------------------------------
-
 ----------------------------------------------------



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^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: Getting one row for each subquery row...?
  2003-06-20 05:12 Getting one row for each subquery row...? Együd Csaba <csegyud@freemail.hu>
@ 2003-06-20 06:07 ` Tomasz Myrta <jasiek@klaster.net>
  1 sibling, 0 replies; 4+ messages in thread

From: Tomasz Myrta @ 2003-06-20 06:07 UTC (permalink / raw)
  To: Együd Csaba <csegyud@freemail.hu>; +Cc: pgsql-sql

Dnia 2003-06-20 07:12, Użytkownik Együd Csaba napisał:
> Hi All,
>  here are my three tables. I wold like to list them in the following way: I
>  need all the columns from t_stockchanges, and one field for the
> productgroup
>  the t_stockchanges.productid belongs to.
> 
>  But one product can belong to many groups, so i would need one row for each
>  group for each product.
> 
>  My bad query is:
>  ------------------------
>  DB=# select t_stockchanges.productid, (select name from t_productgroups
>  where id=(select productgroupid from t_prod_in_pgr where
>  productid=t_stockchanges.productid)) as pgroup from t_stockchanges;
>  ERROR:  More than one tuple returned by a subselect used as an expression.
>  DB=#
>  ---------------
>  Yes, this is absolutelly true, but I would like postgres to give me all the
>  tuples found. How can I ask him to do so?
> 
>  Thank you,
>  -- Csaba
> 
Sure, use "limit 1" in a subquery.

"limit" and "offset" are well described in Postgresql documentation.

Regards,
Tomasz Myrta






^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: Getting one row for each subquery row...?
  2003-06-20 05:12 Getting one row for each subquery row...? Együd Csaba <csegyud@freemail.hu>
@ 2003-06-20 06:11 ` Tomasz Myrta <jasiek@klaster.net>
  2003-06-20 07:02   ` Re: Getting one row for each subquery row...? Együd Csaba <csegyud@freemail.hu>
  1 sibling, 1 reply; 4+ messages in thread

From: Tomasz Myrta @ 2003-06-20 06:11 UTC (permalink / raw)
  To: Együd Csaba <csegyud@freemail.hu>; +Cc: pgsql-sql

Dnia 2003-06-20 07:12, Użytkownik Együd Csaba napisał:

> Hi All,
>  here are my three tables. I wold like to list them in the following way: I
>  need all the columns from t_stockchanges, and one field for the
> productgroup
>  the t_stockchanges.productid belongs to.
> 
>  But one product can belong to many groups, so i would need one row for each
>  group for each product.
> 
>  My bad query is:
>  ------------------------
>  DB=# select t_stockchanges.productid, (select name from t_productgroups
>  where id=(select productgroupid from t_prod_in_pgr where
>  productid=t_stockchanges.productid)) as pgroup from t_stockchanges;
>  ERROR:  More than one tuple returned by a subselect used as an expression.
>  DB=#
>  ---------------
>  Yes, this is absolutelly true, but I would like postgres to give me all the
>  tuples found. How can I ask him to do so?
> 
>  Thank you,
>  -- Csaba
Sorry, if you want all combination of grups and products, you need to rewrite 
your query:

select
  t_stockchanges.productid,
  t_productgroups.name as pgroup
from
  t_stockchanges
  join t_prod_in using (productid)
  join t_productgroups on (id=productgroupid)

or something like this.

Tomasz





^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: Getting one row for each subquery row...?
  2003-06-20 05:12 Getting one row for each subquery row...? Együd Csaba <csegyud@freemail.hu>
  2003-06-20 06:11 ` Re: Getting one row for each subquery row...? Tomasz Myrta <jasiek@klaster.net>
@ 2003-06-20 07:02   ` Együd Csaba <csegyud@freemail.hu>
  0 siblings, 0 replies; 4+ messages in thread

From: Együd Csaba @ 2003-06-20 07:02 UTC (permalink / raw)
  To: Tomasz Myrta <jasiek@klaster.net>; +Cc: pgsql-sql

Thank you Tomasz,
this last one seems to be good - with a little change.

select distinct t_stockchanges.productid, t_productgroups.name as pgroup
from t_stockchanges
join t_prod_in_pgr using (productid)
join t_productgroups on (t_productgroups.id=productgroupid);

Thank you again.
By,
-- Csaba

> Sorry, if you want all combination of grups and products, you need to
rewrite
> your query:
>
> select
>   t_stockchanges.productid,
>   t_productgroups.name as pgroup
> from
>   t_stockchanges
>   join t_prod_in using (productid)
>   join t_productgroups on (id=productgroupid)
>
> or something like this.
>
> Tomasz
>



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^ permalink  raw  reply  [nested|flat] 4+ messages in thread


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Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2003-06-20 05:12 Getting one row for each subquery row...? Együd Csaba <csegyud@freemail.hu>
2003-06-20 06:07 ` Tomasz Myrta <jasiek@klaster.net>
2003-06-20 06:11 ` Tomasz Myrta <jasiek@klaster.net>
2003-06-20 07:02   ` Együd Csaba <csegyud@freemail.hu>

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