Book Image

PostGIS Cookbook - Second Edition

By : Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán
Book Image

PostGIS Cookbook - Second Edition

By: Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán

Overview of this book

PostGIS is a spatial database that integrates the advanced storage and analysis of vector and raster data, and is remarkably flexible and powerful. PostGIS provides support for geographic objects to the PostgreSQL object-relational database and is currently the most popular open source spatial databases. If you want to explore the complete range of PostGIS techniques and expose related extensions, then this book is for you. This book is a comprehensive guide to PostGIS tools and concepts which are required to manage, manipulate, and analyze spatial data in PostGIS. It covers key spatial data manipulation tasks, explaining not only how each task is performed, but also why. It provides practical guidance allowing you to safely take advantage of the advanced technology in PostGIS in order to simplify your spatial database administration tasks. Furthermore, you will learn to take advantage of basic and advanced vector, raster, and routing approaches along with the concepts of data maintenance, optimization, and performance, and will help you to integrate these into a large ecosystem of desktop and web tools. By the end, you will be armed with all the tools and instructions you need to both manage the spatial database system and make better decisions as your project's requirements evolve.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Geocoding and reverse geocoding using the GeoNames datasets


In this recipe, you will write two PL/PostgreSQL PostGIS functions that will let you perform geocoding and reverse geocoding using the GeoNames datasets.

GeoNames is a database of place names in the world, containing over 8 million records that are available for download free of charge. For the purpose of this recipe, you will download a part of the database, load it in PostGIS, and then use it within two functions to perform geocoding and reverse geocoding. Geocoding is the process of finding coordinates from geographical data, such as an address or a place name, while reverse geocoding is the process of finding geographical data, such as an address or place name, from its coordinates.

You are going to write the two functions using PL/pgSQL, which adds on top of the PostgreSQL SQL commands the ability to tie more commands and queries together, a bunch of control structures, cursors, error management, and other goodness.

Getting ready...