Practical PostgreSQL

Introduction to psql

The psql client is a command-line client distributed with PostgreSQL. It is often called the interactive monitor or interactive terminal. With psql, you get a simple yet powerful tool with which you can directly interface with the PostgreSQL server, and thereby begin exploring SQL.

Starting psql

Before starting psql, be sure that you have either copied the psql binary into a path in your system PATH variable (e.g., /usr/bin), or that you have placed the PostgreSQL binary path (e.g., /usr/local/pgsql/bin) within your list of paths in your PATH environment variable (as shown in Chapter 2).

How you set the appropriate PATH variable will depend on your system shell. An example in either bash or ksh might read:

$ export PATH=$PATH:/usr/local/pgsql/bin

An example in either csh or tcsh might read:

$ set path=($path /usr/local/pgsql/bin)

Example 4-1. Setting system path for psql

[user@host user]$ psql
bash: psql: command not found
[user@host user]$ echo $PATH
/bin:/usr/bin:/usr/local/bin:/usr/bin/X11:/usr/X11R6/bin
[user@host user]$ export PATH=$PATH:/usr/local/pgsql/bin
[user@host user]$ psql testdb
Welcome to psql, the PostgreSQL interactive terminal.

Type:  \copyright for distribution terms
       \h for help with SQL commands
       \? for help on internal slash commands
       \g or terminate with semicolon to execute query
       \q to quit

testdb=#

Note that Example 4-1 takes place within a bash shell.

Once you have appropriately set your PATH variable, you should be able to type psql, along with ...