How to Disconnect from a database and go back to the default database in PostgreSQL?

问题

I'm using PostgreSql version :

postgres=# select version();
                           version
-------------------------------------------------------------
 PostgreSQL 9.2.4, compiled by Visual C++ build 1600, 64-bit
(1 row)

i had connected to a database from postgres=# to newdb=#.... Now i'm in newdb=# Database i want to disconnect it and go back to postgres=# database ....

How to do this ?

I have tried with disconnect newdb;

but its giving erroe as::

postgres=# create database newdb;
CREATE DATABASE
postgres=# \c newdb;
WARNING: Console code page (437) differs from Windows code page (1252)
         8-bit characters might not work correctly. See psql reference
         page "Notes for Windows users" for details.
You are now connected to database "newdb" as user "postgres".
newdb=# disconnect newdb;
ERROR:  syntax error at or near "disconnect"
LINE 1: disconnect newdb;
        ^
newdb=#

it isnt working is there any other way to do this or am i wrong in anything!!

回答1:

It's easy, just look the example.

--my databases

postgres=# \l
                               List of databases
   Name    |  Owner   | Encoding | Collate | Ctype |     Access privileges     
-----------+----------+----------+---------+-------+---------------------------
 francs    | postgres | UTF8     | C       | C     | =Tc/postgres             +
           |          |          |         |       | postgres=CTc/postgres    +
           |          |          |         |       | francs=C*T*c*/postgres   +
           |          |          |         |       | select_only=c/francs
 postgres  | postgres | UTF8     | C       | C     | 
 source_db | postgres | UTF8     | C       | C     | =Tc/postgres             +
           |          |          |         |       | postgres=CTc/postgres    +
           |          |          |         |       | source_db=C*T*c*/postgres
 template0 | postgres | UTF8     | C       | C     | =c/postgres              +
           |          |          |         |       | postgres=CTc/postgres
 template1 | postgres | UTF8     | C       | C     | =c/postgres              +
           |          |          |         |       | postgres=CTc/postgres
(5 rows)

--switch to db francs as role francs

postgres=# \c francs francs
You are now connected to database "francs" as user "francs".

--swith to db postgres as role postgres

francs=> \c postgres postgres

You are now connected to database "postgres" as user "postgres".
postgres=#

--disconnect from db

postgres=# \q

回答2:

There is not a 'disconnect' in psql. Instead of disconnecting from your newdb database you connect with the default postgres database.

Create the new database and connect to it:

postgres=# create database newdb;
CREATE DATABASE    
postgres=# \c newdb
You are now connected to database "newdb" as user "postgres".
newdb=#

List the number of connections on newdb:

newdb=# select datname,numbackends from  pg_stat_database where datname='newdb';
 datname | numbackends
---------+-------------
 newdb   |           1

Now, instead of disconnecting, just connect with the default postgres database.

newdb=# \c postgres
You are now connected to database "postgres" as user "postgres".
postgres=#

Now there are no connections on newdb:

postgres=# select datname,numbackends from  pg_stat_database where datname='newdb';
 datname | numbackends
---------+-------------
 newdb   |           0

来源：https://stackoverflow.com/questions/17963348/how-to-disconnect-from-a-database-and-go-back-to-the-default-database-in-postgre

标签

postgresql

postgresql-9.1

postgresql-9.2