How to rectify the geometry of a Postgis table

We have already discussed the topic of geometry validation through a series of articles (in french):

In this article we will discuss, in detail, how to detect and rectify geometric problems in a PostgreSQL / Postgis table using SQL queries.
Continue reading “How to rectify the geometry of a Postgis table”

How to join data from Excel to an attribute table in QGis

The present topic is meant as a brief review since the possibility of loading and attach Excel tables was introduced by QGis 1.8.
As we do not follow the general logic, for new users it is not easy to find the answer. So, step by step, how to make a join between a spatial layer (we’ll take an example here with a shapefile) and a non-spatial table like Excel (with or without XY fields). Continue reading “How to join data from Excel to an attribute table in QGis”