Thread: libpq: possible to get list of tables, fields, and types?

libpq: possible to get list of tables, fields, and types?

From
john heasley
Date:
using libpq, is it possible to get a list of tables (psql: \d equivalent),
list of fields for each of those tables (psql: \d <table>), and types for
each of the fields for a given container?

there doesnt seem to be a way to do any of these, except for getting the
field type of a returned tuple with PQftype() and looking up the returned
oid in the pg_attribute.

it does appear to be possible to query system tables (psql: \dS) for some
of this data, such as pg_tables for a list of tables.  yet there doesnt
appear to be a way to associate these entries to a particular datbase
container.  am i missing some way to glue these tables together to get a
list of tables per-container and fields per-table?

tia,
-heas

Re: libpq: possible to get list of tables, fields, and types?

From
Tommi Mäkitalo
Date:
john heasley wrote:

>using libpq, is it possible to get a list of tables (psql: \d equivalent),
>list of fields for each of those tables (psql: \d <table>), and types for
>each of the fields for a given container?
>
>there doesnt seem to be a way to do any of these, except for getting the
>field type of a returned tuple with PQftype() and looking up the returned
>oid in the pg_attribute.
>
>it does appear to be possible to query system tables (psql: \dS) for some
>of this data, such as pg_tables for a list of tables.  yet there doesnt
>appear to be a way to associate these entries to a particular datbase
>container.  am i missing some way to glue these tables together to get a
>list of tables per-container and fields per-table?
>
>tia,
>-heas
>
>---------------------------(end of broadcast)---------------------------
>TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
>
Hi,

yes - system tables is the right answer.

pg_tables is a view on pg_class. And pg_class has the information you
need. Look into the developers guide for a description of systemtables.

Information about the attributes are in pg_attribute. Just join it with
pg_class:
  select relname, attname, atttypid, attlen from pg_attribute join
pg_class on attrelid = pg_class.oid

A good source for information is pgaccess. It is a TCL-script. You can
find examples in the source.


Tommi


Re: libpq: possible to get list of tables, fields, and types?

From
William WAISSE
Date:
>   select relname, attname, atttypid, attlen from pg_attribute join
> pg_class on attrelid = pg_class.oid

 This gives all the attributes of a given table, but I couldn't find any join
giving all the tables of a particular database ( no dboid in pg_class ).

 Did someone here found this kind of join ?

--
cordialement,  William WAISSE fpr = 9CCD 7DA2 7050 8805 F471  03D1 DF76 B78C
690B 4E07
  --
Computers are like air conditionners. They work better when you close windows.
  --
Visitez donc mon site perso (version 0.4 du 29/05/2001) :
http://www.neofutur.net
  --
Vous habitez dans l'Essonne et vous aimez les Pingouins ???
visitez donc la GAULE(=LUG91) : http://www.gaule.org
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GCS/E/MU d- s: a- C++++ UL+++ P+ L++++ E--- W++ N o-- K- w---
O- M- V- PS+ PE-- Y++ PGP++ t+ 5 X++ R++ tv- b+++ DI- D G e++ h* r++ y+++
------END GEEK CODE BLOCK------