Leveraging the power of spatial databases
Another approach to geoprocessing is to use the functionality provided by spatial databases such as PostGIS and SpatiaLite. In the Loading data from databases section of Chapter 2, Viewing Spatial Data, we discussed how to load data from a SpatiaLite database. In this exercise, we will use SpatiaLite's built-in geoprocessing functions to perform spatial analysis directly in the database and visualize the results in QGIS. We will use the same SpatiaLite database that we downloaded in Chapter 2, Viewing Spatial Data, from www.gaia-gis.it/spatialite-2.3.1/test-2.3.zip (4 MB).
Selecting by location in SpatiaLite
As an example, we will use SpatiaLite's spatial functions to get all highways that are within 1 km distance from the city of Firenze:
To interact with the database, we use the DB Manager plugin, which can be enabled in the Plugin Manager and is available via the Database menu.
Note
If you have followed the Loading data from databases section in Chapter...
