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 [melt93] and [date97] . 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/
  
  .  (Binary
    distributions of
  
   PostgreSQL
  
  might not
    provide those files.)  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. Then, to start the tutorial, do the following:
$psql -s mydb...mydb=>\i basics.sql
  The
  
   \i
  
  command reads in commands from the
    specified file.
  
   psql
  
  's
  
   -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
  
  .