Adding PostGIS layers – QGIS

In this recipe, we will establish a connection to our PostGIS database in order to add a table as a layer in QGIS (formerly known as Quantum GIS). Viewing tables as layers is great for creating maps or simply working on a copy of the database outside the database.

Please navigate to the following site to install the latest version of QGIS (2.0 as of writing this book):

http://qgis.org/en/site/

On this page, click on Download Now and you will be able to choose the suitable operating system and settings. QGIS is available for Android, Linux, Mac OS X, and Windows. You might also be inclined to click on Discover QGIS to get an overview of some basic information about the program, along with features, screenshots, and case studies.

Getting ready

To begin, let's download data from the following U.S. Census Bureau's FTP site:

ftp://ftp2.census.gov/geo/tiger/TIGER2012/EDGES/tl_2012_39035_edges.zip

The shapefile consists of roads, streams, and other line features found...