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

Acting on function results


The previous example showed one way to retrieve and further process function results. The following are a few more useful ways to call a function:

SELECT fib(55);
SELECT (flatten_application_settings('9.08.97')).*
SELECT * FROM flatten_application_settings('9.08.97');

Any of the previous methods will create a legal field list in PostgreSQL, which in turn can be used in any way that fields in a simple SELECT statement on a table are used.

The example from the previous section used the results of the flatten_application_settings() function, a source of data for an INSERT statement. The following is an example of how to use the same function as a data source for UPDATE:

UPDATE application_settings_new 

   SET full_name = flat.full_name,

       description  = flat.description,

       print_certificate = flat.print_certificate,

       show_advertisements = flat.show_advertisements,

       show_splash_screen = flat.show_splash_screen  

  FROM flatten_application_settings...