Book Image

PostgreSQL Server Programming

Book Image

PostgreSQL Server Programming

Overview of this book

Learn how to work with PostgreSQL as if you spent the last decade working on it. PostgreSQL is capable of providing you with all of the options that you have in your favourite development language and then extending that right on to the database server. With this knowledge in hand, you will be able to respond to the current demand for advanced PostgreSQL skills in a lucrative and booming market."PostgreSQL Server Programming" will show you that PostgreSQL is so much more than a database server. In fact, it could even be seen as an application development framework, with the added bonuses of transaction support, massive data storage, journaling, recovery and a host of other features that the PostgreSQL engine provides. This book will take you from learning the basic parts of a PostgreSQL function, then writing them in languages other than the built-in PL/PgSQL. You will see how to create libraries of useful code, group them into even more useful components, and distribute them to the community. You will see how to extract data from a multitude of foreign data sources, and then extend PostgreSQL to do it natively. And you can do all of this in a nifty debugging interface that will allow you to do it efficiently and with reliability.
Table of Contents (17 chapters)
PostgreSQL Server Programming
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Chapter 3. Your First PL/pgSQL Function

A function is the basic building block for extending PostgreSQL. A function accepts input in the form of parameters, and can create output in the form of output parameters or return values. Many functions are provided by PostgreSQL itself such as the common mathematical functions, for example, square root and absolute value. For a comprehensive list of what is already available, go to http://www.postgresql.org/docs/current/static/functions.html.

The functions that you create have all of the same privileges and power that the built-in functions possess. The developers of PostgreSQL use the same libraries to extend the database that you use as a developer to write your business logic.

This means that you have the tools available to be a first class citizen of the PostgreSQL development community. In fact, there are no second-class seats on this bus.

A function accepts parameters that can be of any data type available in PostgreSQL and it returns results...