Introduction

PostGIS is an open source extension for the PostgreSQL database that allows support for geographic objects; throughout this book you will find recipes that will guide you step by step to explore the different functionalities it offers.

The purpose of the book is to become a useful tool for understanding the capabilities of PostGIS and how to apply them in no time. Each recipe presents a preparation stage, in order to organize your workspace with everything you may need, then the set of steps that you need to perform in order to achieve the main goal of the task, that includes all the external commands and SQL sentences you will need (which have been tested in Linux, Mac and Windows environments), and finally a small summary of the recipe. This book will go over a large set of common tasks in geographical information systems and location-based services, which makes it a must-have book in your technical library.

In this first chapter, we will show you a set of recipes covering different tools and methodologies to import and export geographic data from the PostGIS spatial database, given that pretty much every common action to perform in a GIS starts with inserting or exporting geospatial data.