> Objective

• This section contains information on how to work with spatial databases.  

• The student will learn how to use PostGIS in QGIS.   

• The student will learn how to use PostgreSQL in QGIS. 

> Index / Table of Contents

• Introduction  

• Tutorial(s)  

  • Spatial databases  

  • PostGIS  

  • PostgreSQL  

• QGIS installation  

> Summary and Highlights

Introduction  

This section addresses how to use databases in QGIS. A database is a structured collection of data stored on and accessible through a computer system.  

The following tutorials make use of PostgreSQL and PostGIS. PostgreSQL is an open source object-relational database system that uses the Structured Query Language (SQL) language to manage data. PostGIS is an extender for PostgreSQL and help to manage geographic objects. QGIS also supports SpatiaLite databases, which allow to store an entire database in a single file. 

Tutorial(s) 

Spatial Databases  

A spatial database contains data related to objects defined in space. 

• How to work with spatial databases   QGIS Training manual: “18. Module: Using Spatial Databases in QGIS”   Language(s): English  Chapters: working with databases in the QGIS browser, using DB Manager to work with spatial databases in QGIS, working with SpatiaLite databases in QGIS   https://docs.qgis.org/3.10/en/docs/training_manual/databases/index.html  

PostGIS 

PostGIS is a spatial database extender for PostgreSQL object-relational database. It allows location queries to run in SQL. 

• Setup a spatial database, import data and make use of the geographic functions of PostGIS  QGIS Training manual: “16. Module: Spatial Database Concepts with PostGIS”  Language(s): English   Chapters: PostGIS setup, simple feature model, import and export, spatial queries, geometry construction   https://docs.qgis.org/3.10/en/docs/training_manual/spatial_databases/index.html  

• Create a database, add a PostGIS extension and load layers via the DB-manager   Mariëlle Geers-Plasmans (Geojuffie): “Introductie PostGIS”  Language(s): Dutch   Time: 14m 4s  https://www.youtube.com/watch?v=QeejezwhhdQ  

• Introduction to SQL queries   Mariëlle Geers-Plasmans (Geojuffie): “SQL in PostGIS”  Language(s): Dutch   Time: 7m 2s  https://www.youtube.com/watch?v=pDetUNQ8gaw  

• Join tables in PostGIS   Mariëlle Geers-Plasmans (Geojuffie): “Join in PostGIS”  Language(s): Dutch   Time: 5m 34s  https://www.youtube.com/watch?v=bxgJot-g85Q  

PostgreSQL 

PostgreSQL is an object-relational database management system. It uses the SQL language, is free, open source and highly extensible. 

• Learn about databases and PostgreSQL    QGIS Training manual: “15. Module: Database Concepts with PostgreSQL”  Language(s): English   Chapters: introduction to databases, implementing the data model, adding data to the model, queries, views, rules    https://docs.qgis.org/3.10/en/docs/training_manual/database_concepts/index.html  

> QGIS Installation

Do you still need to install QGIS? The QGIS installation and update section explains how to install QGIS on Windows and macOS. 

Useful Links

QGIS Training Manual

QGIS User Guide

GIS OpenCourseWare

PostgreSQL documentation

PostGIS documentation

SpatiaLite

Mariëlle Geers-Plasmans (Geojuffie) YouTube channel

#QGIS, #Databases, #PostgreSQL, #PostGIS, #SpatiaLite, #SQL