Book Image

PostgreSQL Development Essentials

By : Baji Shaik
Book Image

PostgreSQL Development Essentials

By: 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 (12 chapters)

Helper functions to deal with data fetching

There are other helper functions that help you retrieve the results. Let's go through these functions one by one:

pg_free_results

Using the pg_free_results function, we can clear the memory resources that are used to hold the result set. All the data retrieval functions we used earlier occupy a certain amount of memory to hold the result set. It is a good practice to clear the result set after we are done processing the query results.

pg_num_rows

Using the pg_num_rows function, we can get the number of tuples in the result set. That is, if we execute a query, it returns the number of tuples the SELECT query has fetched from the database.

pg_num_fields

Using the pg_num_fields function, we can get the number of columns or fields in the result set. That is, it returns the number of columns we mentioned in the SELECT query.

pg_field_name

Using pg_field_name function, we can get the field name that we mentioned in the SELECT query. This...