Обсуждение: current_schemas()

I would like to know how to use current_schemas(), since SELECT current_schemas(); didn't work in
PostgreSQL 7.4 and 8.0 psql.

Halley

PostgreSQL 8.0.3 Documentation
Chapter 16. Server Run-time Environment
16.4. Run-time Configuration

The current effective value of the search path can be examined via the SQL function
current_schemas(). This is not quite the same as examining the value of search_path, since
current_schemas() shows how the requests appearing in search_path were resolved.

teste=# \dn
********* QUERY **********
SELECT n.nspname AS "Name",
       u.usename AS "Owner"
FROM pg_catalog.pg_namespace n LEFT JOIN pg_catalog.pg_user u
       ON n.nspowner=u.usesysid
WHERE   (n.nspname NOT LIKE 'pg\\_temp\\_%' OR
                 n.nspname = (pg_catalog.current_schemas(true))[1])
ORDER BY 1;
**************************

        List of schemas
        Name        |  Owner
--------------------+----------
 information_schema | postgres
 pg_catalog         | postgres
 pg_toast           | postgres
 public             | postgres
(4 rows)

teste=# SELECT current_schema();
 current_schema
----------------
 public
(1 row)

teste=# SELECT current_schemas();
ERROR:  function current_schemas() does not exist
HINT:  No function matches the given name and argument types. You may need to add explicit type
casts.







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On Tue, Jul 05, 2005 at 08:14:40AM -0300, Halley Pacheco de Oliveira wrote:

> teste=# SELECT current_schemas();
> ERROR:  function current_schemas() does not exist
> HINT:  No function matches the given name and argument types. You may need to add explicit type
> casts.

alvherre=# select current_schemas(true);
   current_schemas
---------------------
 {pg_catalog,public}
(1 fila)

alvherre=# select current_schemas(false);
 current_schemas
-----------------
 {public}
(1 fila)


Function parameters are essential when determining if a function exists
or not.

alvherre=# \df current_schema*
                                 Listado de funciones
   Schema   |     Nombre      | Tipo de dato de salida | Tipos de datos de argumentos
------------+-----------------+------------------------+------------------------------
 pg_catalog | current_schema  | name                   |
 pg_catalog | current_schemas | name[]                 | boolean
(2 filas)

--
Alvaro Herrera (<alvherre[a]surnet.cl>)
FOO MANE PADME HUM

Why not just use pg_catalog.current_schemas()?

---------------------------------------------------------------------------

Halley Pacheco de Oliveira wrote:
> I would like to know how to use current_schemas(), since SELECT current_schemas(); didn't work in
> PostgreSQL 7.4 and 8.0 psql.
>
> Halley
>
> PostgreSQL 8.0.3 Documentation
> Chapter 16. Server Run-time Environment
> 16.4. Run-time Configuration
>
> The current effective value of the search path can be examined via the SQL function
> current_schemas(). This is not quite the same as examining the value of search_path, since
> current_schemas() shows how the requests appearing in search_path were resolved.
>
> teste=# \dn
> ********* QUERY **********
> SELECT n.nspname AS "Name",
>        u.usename AS "Owner"
> FROM pg_catalog.pg_namespace n LEFT JOIN pg_catalog.pg_user u
>        ON n.nspowner=u.usesysid
> WHERE   (n.nspname NOT LIKE 'pg\\_temp\\_%' OR
>                  n.nspname = (pg_catalog.current_schemas(true))[1])
> ORDER BY 1;
> **************************
>
>         List of schemas
>         Name        |  Owner
> --------------------+----------
>  information_schema | postgres
>  pg_catalog         | postgres
>  pg_toast           | postgres
>  public             | postgres
> (4 rows)
>
> teste=# SELECT current_schema();
>  current_schema
> ----------------
>  public
> (1 row)
>
> teste=# SELECT current_schemas();
> ERROR:  function current_schemas() does not exist
> HINT:  No function matches the given name and argument types. You may need to add explicit type
> casts.
>
>
>
>
>
>
>
> _______________________________________________________
> Yahoo! Acesso Gr?tis - Internet r?pida e gr?tis.
> Instale o discador agora! http://br.acesso.yahoo.com/
>
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--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

On Fri, Jul 29, 2005 at 10:30:13PM -0400, Bruce Momjian wrote:
>
> Why not just use pg_catalog.current_schemas()?

The function is current_schemas(bool), that's why this example doesn't
work:

> > teste=# SELECT current_schemas();
> > ERROR:  function current_schemas() does not exist
> > HINT:  No function matches the given name and argument types. You may need to add explicit type casts.

--
Alvaro Herrera (<alvherre[a]alvh.no-ip.org>)
"Aprende a avergonzarte más ante ti que ante los demás" (Demócrito)