Introduction to SQL and Geospatial Data Processing

Mapping

Overview

Teaching: 10 min
Exercises: 20 min
Questions

  • How do I plot the results of spatial queries on a map?

Objectives

  • Learn about the various options for visualizing geospatial datasets.

Plotting your data on a map:

  1. Download the QGIS software
  2. Run the software and connect to the database:
    • click on “layer/add PostGIS layers”
    • click on the “new” button and enter the connection information (similar to what you did in exercise 1 for the pgadmin software)
    • click on the “connect” button
    • you should now see the database tables we’ve been working with. Add one of these and it should appear on the map.
  3. Things to explore next:
    • change the symbology of the points, coloring them by a specific attribute so that the colors illustrate grouping in the data
    • add a background map web\QuickMapServices\OSM
    • issue the SQL query you built above to select only those points within 1 km of a point
      • click on database\DBmanager and you will see the database to which you have already connected.
      • issue a SQL query in the SQL command window (blue arrow in this screen capture):

Challenge: Try to make a map like this!

Additional resources

Key Points