I'm using QGIS 1.8. I have 3 files: a shapefile from a state, a CSV file with a common field with this shape file and a third file (CSV, with long/lat columns).
In this third file. I have a column 'id_customer'. The shapefile is a map of a state. And the file with a common column with the shapefile, has the income for various neighbourhoods. I want to link the customer file with the shape, and after link the customer to the income field.
Can anyone help me?