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

Running database queries – OpenJUMP GIS


Executing ad hoc queries in OpenJUMP is simple and offers a couple of unique features. Queries can be run on specific data selections, allowing for the manual control of the queried area without considering the attribution. Similarly, temporary fences (areas) can be drawn on the fly and the geometry of the surface can be used in queries. In this recipe, we will explore each of those cases.

Getting ready

Refer to the preceding recipe if you need to install OpenJUMP or require assistance connecting to a database.

How to do it...

Carry out the following steps to run the data store query:

  1. Navigate to File | Run Datastore Query. Choose the PostGIS connection from the Connection drop-down menu or use the Connection Manager utility if you are not linked to the database.
  2. We'll create and name a polygon layer of the main streams in the region by executing the following query:
SELECT gid, ST_BUFFER("chp11".lines.geom_sp, 75) 
      AS the_geom, fullname 
      FROM...