This chapter explains various methods of accessing the database. Assume that we have already created a database in our previous chapter. You can select the database using either of the following methods −
- Database SQL Prompt
- OS Command Prompt
Database SQL Prompt
Assume you have already launched your PostgreSQL client and you have landed at the following SQL prompt −
postgres=#
You can check the available database list using \l, i.e., backslash el command as follows −
postgres-# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+---------+-------+-----------------------
postgres | postgres | UTF8 | C | C |
template0 | postgres | UTF8 | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
testdb | postgres | UTF8 | C | C |
(4 rows)
postgres-#
Now, type the following command to connect/select a desired database; here, we will connect to the testdb database.
postgres=# \c testdb; psql (9.2.4) Type "help" for help. You are now connected to database "testdb" as user "postgres". testdb=#
OS Command Prompt
You can select your database from the command prompt itself at the time when you login to your database. Following is a simple example −
psql -h localhost -p 5432 -U postgress testdb Password for user postgress: **** psql (9.2.4) Type "help" for help. You are now connected to database "testdb" as user "postgres". testdb=#
You are now logged into PostgreSQL testdb and ready to execute your commands inside testdb. To exit from the database, you can use the command \q.