Book Image

PostgreSQL Development Essentials

By : Manpreet Kaur, Baji Shaik
Book Image

PostgreSQL Development Essentials

By: Manpreet Kaur, Baji Shaik

Overview of this book

PostgreSQL is the most advanced open source database in the world. It is easy to install, configure, and maintain by following the documentation; however, it’s difficult to develop applications using programming languages and design databases accordingly. This book is what you need to get the most out of PostgreSQL You will begin with advanced SQL topics such as views, materialized views, and cursors, and learn about performing data type conversions. You will then perform trigger operations and use trigger functions in PostgreSQL. Next we walk through data modeling, normalization concepts, and the effect of transactions and locking on the database. The next half of the book covers the types of indexes, constrains, and the concepts of table partitioning, as well as the different mechanisms and approaches available to write efficient queries or code. Later, we explore PostgreSQL Extensions and Large Object Support in PostgreSQL. Finally, you will perform database operations in PostgreSQL using PHP and Java. By the end of this book, you will have mastered all the aspects of PostgreSQL development. You will be able to build efficient enterprise-grade applications with PostgreSQL by making use of these concepts
Table of Contents (17 chapters)
PostgreSQL Development Essentials
About the Authors
About the Reviewers

Data retrieval

To retrieve records from the database, we can use the same functions that we used to INSERT records into a database, except pg_insert(). To retrieve the records or to navigate tuples one by one, we need to use some other functions where we can traverse the complete query result set.

Now let's discuss query retrieval functions one by one.


Once we execute our SQL query using pg_execute, pg_query, or pg_query_params, we can use pg_fetch_all; this takes the data resource as an argument and returns an array, which holds our complete query result set.

The following is an example:

$res=pg_query($con, "SELECT * FROM test"); 
echo"Complete result set\n"; 

In the preceding PHP code, we used $res as an argument for pg_fetch_all(). which is a pointer to the query result set.


$ php /tmp/test.php 
Successfully made connection...