Postgres Pro
Downloads
Home   >   mailing lists

Thread: SQL Query for Top Down fetching of childs

SQL Query for Top Down fetching of childs

From
"Kumar"
Date:
Dear Friends,
 
Postgres 7.3.4 on RH Linux 7.2.
 
I need a query to get the Childs of a parent (Top down analysis). Need to list all the departments(Childs) of a parent organization. The table structure is
 
CREATE TABLE organization
(
  entity_id int4,
  entity_name varchar(100),
  entity_type varchar(25),
  parent_entity_id int4,
) WITH OIDS;
 
A parent can have n number of Childs. So I need to list all the childs for a parent.
 
For example I query the Division , then it lists it Childs
# select * from organization where parent_entity_id = 3;
 entity_id | entity_name |   entity_type   | parent_entity_id
-----------+-------------+-----------------+------------------
         5 | HR          | EngineeringTeam |                3
        12 | PM          | EngineeringTeam |                3
         8 | Finance     | Dept            |                3
         6 | Quality     | Dept            |                3
 
 
I need to drill down to the last level Engineering Team in this example.
So I query entity_id 8 further, it gives me its Childs
=# select * from organization where parent_entity_id = 8;
 entity_id | entity_name | entity_type | parent_entity_id
-----------+-------------+-------------+------------------
        15 | Audit       | Group       |                8
        16 | Mkt         | Group       |                8
(2 rows)
 
Again, I need to query the entity_id 15 to get its child
=# select * from organization where parent_entity_id = 15;
 entity_id | entity_name |   entity_type   | parent_entity_id
-----------+-------------+-----------------+------------------
        17 | CA          | EngineeringTeam |               15
        18 | Comm        | EngineeringTeam |               15
        19 | EComm       | EngineeringTeam |               15
(3 rows)
 
I have used the following query, but not useful.
 
 
CREATE OR REPLACE FUNCTION.fn_get_all_organization(int4)
  RETURNS SETOF organization AS
'DECLARE
 pi_entity_id ALIAS FOR $1;
 rec_result  organization%ROWTYPE;
 rec_proc  organization%ROWTYPE;
 v_patent_entity_id INT;
 
BEGIN
 FOR rec_result IN SELECT entity_id, entity_name, entity_type, parent_entity_id FROM organization ben
                            WHERE ben.parent_entity_id = pi_entity_id
 LOOP
  IF rec_result.entity_type = \'EngineeingTeam\' THEN
       RETURN NEXT rec_result;
  ELSE
       v_patent_entity_id := rec_result.entity_id;
   LOOP
       FOR rec_proc IN SELECT bse.entity_id, bse.entity_name, bse.entity_type, bse.parent_entity_id FROM organization bse
                                 WHERE bse.parent_entity_id= v_patent_entity_id
    LOOP
    IF rec_proc.entity_type = \'EngineeringTeam\' THEN
         RETURN NEXT rec_proc;
    ELSE
         v_patent_entity_id := rec_proc.entity_id;
   END IF;
   END LOOP;
   EXIT WHEN rec_proc.entity_type = \'EngineeringTeam\';
   END LOOP;
  END IF; 
 END LOOP;
RETURN;
END;'
  LANGUAGE 'plpgsql' VOLATILE;
 
Anybody pls help me with this. I am first time writing these kind of function for TOP DOWN analysis. Please shed light.
 
Regards
Senthil Kumar S
 

Re: SQL Query for Top Down fetching of childs

From
Richard Huxton
Date:
On Thursday 29 January 2004 06:11, Kumar wrote:
> Dear Friends,
>
> Postgres 7.3.4 on RH Linux 7.2.
>
> I need a query to get the Childs of a parent (Top down analysis). Need to
> list all the departments(Childs) of a parent organization. The table
> structure is

Two places to look for examples:
1. the contrib/tablefunc folder has an example of this sort of thing
2. search the mailing list articles for CONNECT BY (oracle's name for this 
sort of thing) or "tree"

--  Richard Huxton Archonet Ltd

Re: SQL Query for Top Down fetching of childs

From
"Kumar"
Date:
Thanks a lot Mr.Richard Huxton. It managed to find a similar one and
modified to my need. It is working fine. Thanks a lot
----- Original Message ----- 
From: "Richard Huxton" <dev@archonet.com>
To: "Kumar" <sgnerd@yahoo.com.sg>; "psql" <pgsql-sql@postgresql.org>
Sent: Thursday, January 29, 2004 3:57 PM
Subject: Re: [SQL] SQL Query for Top Down fetching of childs


> On Thursday 29 January 2004 06:11, Kumar wrote:
> > Dear Friends,
> >
> > Postgres 7.3.4 on RH Linux 7.2.
> >
> > I need a query to get the Childs of a parent (Top down analysis). Need
to
> > list all the departments(Childs) of a parent organization. The table
> > structure is
>
> Two places to look for examples:
> 1. the contrib/tablefunc folder has an example of this sort of thing
> 2. search the mailing list articles for CONNECT BY (oracle's name for this
> sort of thing) or "tree"
>
> -- 
>   Richard Huxton
>   Archonet Ltd
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
>       subscribe-nomail command to majordomo@postgresql.org so that your
>       message can get through to the mailing list cleanly