PostgreSQL, Second Edition

Retrieving Data from the Sample Database

At this point, you should have a sample database (movies) that contains three tables (tapes, customers, and rentals) and a few rows in each table. You know how to get data into a table; now let's see how to view that data.

The SELECT statement is used to retrieve data from a database. SELECT is the most complex statement in the SQL language, and the most powerful. Using SELECT, you can retrieve entire tables, single rows, a group of rows that meet a set of constraints, combinations of multiple tables, expressions, and more. To help you understand the basics of the SELECT statement, I'll try to break it down into each of its forms and move from the simple to the more complex.

SELECT Expression

In its simplest ...