2.1. Introduction

This chapter provides an overview of how to use SQL to perform simple operations. This tutorial is only intended to give you an introduction and is in no way a complete tutorial on SQL . Numerous books have been written on SQL , including Understanding the New SQL and A Guide to the SQL Standard . You should be aware that some PostgreSQL language features are extensions to the standard.

In the examples that follow, we assume that you have created a database named mydb , as described in the previous chapter, and have been able to start psql .

Examples in this manual can also be found in the PostgreSQL source distribution in the directory src/tutorial/ . To use those files, first change to that directory and run make :

$ cd .... /src/tutorial $ make

This creates the scripts and compiles the C files containing user-defined functions and types. (If you installed a pre-packaged version of PostgreSQL rather than building from source, look for a directory named tutorial within the PostgreSQL documentation. The "make" part should already have been done for you.) Then, to start the tutorial, do the following:

$ cd .... /tutorial $ psql -s mydb ... mydb=> \i basics.sql

The \i command reads in commands from the specified file. The -s option puts you in single step mode which pauses before sending each statement to the server. The commands used in this section are in the file basics.sql .