Book Image

Learning QGIS 2.0

By : Anita Graser
Book Image

Learning QGIS 2.0

By: Anita Graser

Overview of this book

QGIS is a user friendly open source geographic information system (GIS) that runs on Linux, Unix, Mac OSX, and Windows. The popularity of open source geographic information systems and QGIS in particular has been growing rapidly over the last few years. More and more companies and institutions are adopting QGIS and even switching to QGIS as their main GIS. Learning QGIS 2.0 is a practical, hands-on guide that provides you with clear, step-by-step exercises that will help you to apply your GIS knowledge to QGIS. Containing a number of clear, practical exercises, this book will introduce you to working with QGIS, quickly and painlessly. If you want to take advantage of the wide range of functionalities that QGIS offers, then this is the book for you. This book takes you from installing and configuring QGIS, through handling spatial data to creating great maps. You will learn how to load and visualize existing spatial data and how to create data from scratch. You will perform common geoprocessing and spatial analysis tasks and automate them. We will cover how to achieve great cartographic output and print maps. You will learn everything you need to know to handle spatial data management, processing, and visualization tasks in QGIS.
Table of Contents (12 chapters)

Loading data from databases


QGIS supports PostGIS, SpatiaLite, MSSQL, SQL Anywhere, and Oracle Spatial databases. We will cover the two open source options: PostGIS and SpatiaLite. Both are available cross-platform, just like QGIS.

SpatiaLite is the spatial extension for Sqlite databases. Sqlite is a self-contained, serverless, zero-configuration, transactional SQL database engine (www.sqlite.org). This basically means that an Sqlite database, and therefore also a SpatiaLite database, doesn't need a server installation, and can be copied and exchanged just like any ordinary file.

You can download an example database from www.gaia-gis.it/spatialite-2.3.1/test-2.3.zip. Unzip the file; you will be able to connect to it by going to Layer | Add SpatiaLite Layer, using the Add SpatiaLite Layer toolbar button, or by pressing Ctrl + Shift + L. Click on New to select the database file test-2.3.sqlite. QGIS will save all connections and add them to the drop-down list at the top. After clicking on...