Re: [Pgsql-ayuda] Listado de tablas

Hola:

On Fri, 4 Oct 2002, AAAGU wrote:

> Holas,
> soy nuevo en esto. Alguien podria decirme si es
> posible obtener un listado con los campos de
> determinada tabla si, por ejemplo, estoy trabajando
> con Java y Postgresql?
> Gracias.

Si ejecutas psql con el parámetro -E puedes ver las consultas que genear los comandos internos, entre ellos el comando \d:

Por ejemplo:
\d pais

genera:

********* QUERY **********
SELECT relhasindex, relkind, relchecks, reltriggers, relhasrules
FROM pg_class WHERE relname='pais'
**************************

********* QUERY **********
SELECT a.attname, format_type(a.atttypid, a.atttypmod), a.attnotnull, a.atthasdef, a.attnum
FROM pg_class c, pg_attribute a
WHERE c.relname = 'pais'
AND a.attnum > 0 AND a.attrelid = c.oid
ORDER BY a.attnum
**************************

********* QUERY **********
SELECT substring(d.adsrc for 128) FROM pg_attrdef d, pg_class c
WHERE c.relname = 'pais' AND c.oid = d.adrelid AND d.adnum = 1
**************************

********* QUERY **********
SELECT c2.relname
FROM pg_class c, pg_class c2, pg_index i
WHERE c.relname = 'pais' AND c.oid = i.indrelid AND i.indexrelid = c2.oid
AND NOT i.indisunique ORDER BY c2.relname
**************************

********* QUERY **********
SELECT c2.relname
FROM pg_class c, pg_class c2, pg_index i
WHERE c.relname = 'pais' AND c.oid = i.indrelid AND i.indexrelid = c2.oid
AND i.indisprimary AND i.indisunique ORDER BY c2.relname
**************************

********* QUERY **********
SELECT c2.relname
FROM pg_class c, pg_class c2, pg_index i
WHERE c.relname = 'pais' AND c.oid = i.indrelid AND i.indexrelid = c2.oid
AND NOT i.indisprimary AND i.indisunique ORDER BY c2.relname
**************************

********* QUERY **********
SELECT t.tgname
FROM pg_trigger t, pg_class c
WHERE c.relname='pais' AND c.oid = t.tgrelid
**************************

Table "pais"
Column | Type | Modifiers
-------------+-----------------------+-------------------------------------------------
id | integer | not null default nextval('"pais_id_seq"'::text)
descripcion | character varying(30) |
Primary key: pais_pkey
Triggers: RI_ConstraintTrigger_153561,
RI_ConstraintTrigger_153563

La que necesitas es:

SELECT a.attname, format_type(a.atttypid, a.atttypmod), a.attnotnull, a.atthasdef, a.attnum
FROM pg_class c, pg_attribute a
WHERE c.relname = 'pais'
AND a.attnum > 0 AND a.attrelid = c.oid
ORDER BY a.attnum

pero tal ves debes pedir menos campos.

Saludos,

Roberto Andrade Fonseca
randrade(at)abl(dot)com(dot)mx