PostgreSQL 7.3.2 Tutorial

PostgreSQL 7.3.2 Tutorial The PostgreSQL Global Development Group PostgreSQL 7.3.2 Tutorial by The PostgreSQL Global Development Group Copyright © 1996-2002 by The PostgreSQL Global Development Group Legal Notice PostgreSQL is Copyright © 1996-2002 by the PostgreSQL Global Development Group and is distributed under the terms of the license of the University of California below. Postgres95 is Copyright © 1994-5 by the Regents of the University of California. Permission to use, copy, modify, and distribute this software and its documentation for any purpose, without fee, and without a written agreement is hereby granted, provided that the above copyright notice and this paragraph and the following two paragraphs appear in all copies. IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCI- DENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IM- PLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HERE- UNDER IS ON AN “AS-IS” BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. Table of Contents Preface .........................................................................................................................................................i 1. What is PostgreSQL?......................................................................................................................i 2. A Short History of PostgreSQL ......................................................................................................i 2.1. The Berkeley POSTGRES Project ................................................................................... ii 2.2. Postgres95......................................................................................................................... ii 2.3. PostgreSQL...................................................................................................................... iii 3. What’s In This Book .....................................................................................................................iv 4. Overview of Documentation Resources........................................................................................iv 5. Terminology and Notation .............................................................................................................v 6. Bug Reporting Guidelines.............................................................................................................vi 6.1. Identifying Bugs...............................................................................................................vi 6.2. What to report...................................................................................................................vi 6.3. Where to report bugs ..................................................................................................... viii 1. Getting Started.......................................................................................................................................1 1.1. Installation...................................................................................................................................1 1.2. Architectural Fundamentals ........................................................................................................1 1.3. Creating a Database ....................................................................................................................2 1.4. Accessing a Database..................................................................................................................3 2. The SQL Language................................................................................................................................6 2.1. Introduction.................................................................................................................................6 2.2. Concepts......................................................................................................................................6 2.3. Creating a New Table..................................................................................................................6 2.4. Populating a Table With Rows....................................................................................................7 2.5. Querying a Table.........................................................................................................................8 2.6. Joins Between Tables ..................................................................................................................9 2.7. Aggregate Functions .................................................................................................................11 2.8. Updates......................................................................................................................................13 2.9. Deletions ...................................................................................................................................14 3. Advanced Features...............................................................................................................................15 3.1. Introduction...............................................................................................................................15 3.2. Views.........................................................................................................................................15 3.3. Foreign Keys .............................................................................................................................15 3.4. Transactions ..............................................................................................................................16 3.5. Inheritance.................................................................................................................................17 3.6. Conclusion ................................................................................................................................19 Bibliography.............................................................................................................................................20 Index..........................................................................................................................................................22 iii Preface 1. What is PostgreSQL? PostgreSQL is an object-relational database management system (ORDBMS) based on POSTGRES, Version 4.21, developed at the University of California at Berkeley Computer Science Department. The POSTGRES project, led by Professor Michael Stonebraker, was sponsored by the Defense Advanced Research Projects Agency (DARPA), the Army Research Office (ARO), the National Science Foundation (NSF), and ESL, Inc. PostgreSQL is an open-source descendant of this original Berkeley code. It provides SQL92/SQL99 lan- guage support and other modern features. POSTGRES pioneered many of the object-relational concepts now becoming available in some commer- cial databases. Traditional relational database management systems (RDBMS) support a data model con- sisting of a collection of named relations, containing attributes of a specific type. In current commercial systems, possible types include floating point numbers, integers, character strings, money, and dates. It is commonly recognized that this model is inadequate for future data-processing applications. The relational model successfully replaced previous models in part because of its “Spartan simplicity”. However, this simplicity makes the implementation of certain applications very difficult. PostgreSQL offers substantial additional power by incorporating the following additional concepts in such a way that