Loading data from databases

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

SpatiaLite is the spatial extension for SQLite databases. SQLite is a self-contained, server-less, zero-configuration, and transactional SQL database engine (www.sqlite.org). This basically means that a 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 (4 MB). Unzip the file; you will be able to connect to it by going to Layer | Add Layer | Add SpatiaLite Layer, using the Add SpatiaLite Layer toolbar button, or by pressing Ctrl + Shift + L. Click on New to select the test-2.3.sqlite database file. QGIS will save all the connections and add them to the drop-down list at the top. After...