Book Image

Mastering PostGIS

By : Dominik Mikiewicz, Michal Mackiewicz , Tomasz Nycz
Book Image

Mastering PostGIS

By: Dominik Mikiewicz, Michal Mackiewicz , Tomasz Nycz

Overview of this book

PostGIS is open source extension onf PostgreSQL object-relational database system that allows GIS objects to be stored and allows querying for information and location services. The aim of this book is to help you master the functionalities offered by PostGIS- from data creation, analysis and output, to ETL and live edits. The book begins with an overview of the key concepts related to spatial database systems and how it applies to Spatial RMDS. You will learn to load different formats into your Postgres instance, investigate the spatial nature of your raster data, and finally export it using built-in functionalities or 3th party tools for backup or representational purposes. Through the course of this book, you will be presented with many examples on how to interact with the database using JavaScript and Node.js. Sample web-based applications interacting with backend PostGIS will also be presented throughout the book, so you can get comfortable with the modern ways of consuming and modifying your spatial data.
Table of Contents (9 chapters)

Exporting data using GIS clients


Exporting data using GIS clients is no different to what we have seen already: simply connect to a database, read the data, and then output to a format of your choice. Once a connection can be established, the output formats are totally up to the client used.

In this section, we'll use two GIS clients:QGIS and Manifold.

Exporting data using QGIS

In order to connect to PostGIS from QGIS, go to Database\DB Manager and pick DB Manager. DB Manager is a very powerful tool that lets one not only simply connect and read data from a database, but also manage the database objects, such as tables, their columns, constraints, and indexes. In this scenario, we will not go into the details of how to manage a database using QGIS DB Manger, but instead we will focus on the task and simply use it to get to the data we want exported.

First, let's make sure we can connect to our database. When you expand the database node, you will see the schemas present in the database:

If you...