Book Image

Learning PostgreSQL 10 - Second Edition

Book Image

Learning PostgreSQL 10 - Second Edition

Overview of this book

PostgreSQL is one of the most popular open source databases in the world, supporting the most advanced features included in SQL standards. This book will familiarize you with the latest features released in PostgreSQL 10. We’ll start with a thorough introduction to PostgreSQL and the new features introduced in PostgreSQL 10. We’ll cover the Data Definition Language (DDL) with an emphasis on PostgreSQL, and the common DDL commands supported by ANSI SQL. You’ll learn to create tables, define integrity constraints, build indexes, and set up views and other schema objects. Moving on, we’ll cover the concepts of Data Manipulation Language (DML) and PostgreSQL server-side programming capabilities using PL/pgSQL. We’ll also explore the NoSQL capabilities of PostgreSQL and connect to your PostgreSQL database to manipulate data objects. By the end of this book, you’ll have a thorough understanding of the basics of PostgreSQL 10 and will have the necessary skills to build efficient database solutions.
Table of Contents (23 chapters)
Title Page
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Chapter 15. Using PostgreSQL in Python Applications

A database is a storage component of a software solution. However, it does not just store information, it also ensures consistency when the data is properly modeled in relational structures. Additionally, a database can implement more complicated logic related to consistency, which goes beyond normalization, with triggers and rules. Of course, business logic can also be fulfilled by a database with functions written in PostgreSQL in PL/pgSQL or other languages supported by the DBMS. Implementation of business logic in a database is questionable from an architecture point of view but this is out of topic here.

Nevertheless, the tasks related to interaction with users or I/O cannot be performed by the database. External applications do this. In this chapter, you will learn how to connect and interact with a database from an external application written in Python.

Python is a language that is very easy to learn and quite powerful at the same...