Archive for the ‘GIS’ Category
Ordnance Survey’s Code-Point with Polygons “provides a precise geographical location for each postcode unit in Great Britain”. It’s available in various formats, including ESRI .shp files.
Many UK academics can access the data via institutional subscription to EDINA Digimap. I’m using it in my research into subjective wellbeing and environmental quality.
This post shows how to:
- import the data files into a PostGIS database; and
- de-normalise the data into a single table, where there’s a one-to-one mapping of postcodes to rows, and each row contains either all geographical locations covered by a postcode (as a single geometry column, of type multipolygon) or the reason why no such location is available
This isn’t a very difficult task, but creating the table is somewhat laborious, so perhaps you’ll find the following SQL helpful.