Useful Plugin for QGIS!!

PgQuery is a plugin for QGIS which allows you to execute sql with postgis functionality, and load the results directly as layers with geometry.

a longer writeup can be found here,

As a test, I executed the following query to get all the building footprints in a given neighborhood

SELECT "BLDG_ID","Buildings".the_geom,hood.pri_neigh
(SELECT * FROM neighboorhoods WHERE neighboorhoods.pri_neigh = 'Lincoln Park') AS hood,
WHERE st_contains(hood.geom,"Buildings".the_geom) = true

Check it out! this should be really useful for you!!!


Shapefile to PostGIS Import

I’m trying to import the Shapefile for building footprints in Chicago to PostGIS using Spit on qGIS, but I’ve forgot what was the SRID I was supposed to use.

Could anyone help me with that? Thanks (sorry for this kind of post but I figured it was the quickest way to get an answer and to get the thing going)

Links from class

QGIS tutorials by Gandhi
Quantum GIS (QGIS) Tutorials
Quantum GIS (QGIS) Tutorials: Using Tabular Data in QGIS
Quantum GIS (QGIS) Tutorials: Tutorial: Styling Vector Data in QGIS – Basics
Quantum GIS (QGIS) Tutorials: Tutorial: Spatial Analysis – Points in Polygon
Quantum GIS (QGIS) Tutorials: Tutorial: Performing Spatial Queries in QGIS
Quantum GIS (QGIS) Tutorials: Tutorial: Working with Attribute Table – Basic Queries

PostGIS function reference
PostGIS book I mentioned
Chapter 8. PostGIS Reference

Purely SQL
W3 Schools SQL Reference
SQL GROUP BY Statement
SQL: COUNT Function
SQL COUNT() Function

Where we might go time permitting
15 Advanced PostgreSQL Commands with Examples