Practical GIS

Joining tables

While superfluous columns are often present in general data, it is not rare if we don't have the required attributes we would like to work with. If we are lucky, we can generate them based on other existing attributes, although we should not worry if this is not the case. If we can prepare a table which can be joined to the existing one on a matching column, we can easily join them together.

For this example, I prepared a small table containing descriptions of our GeoNames layer's featureclass and featurecodes columns based on the official GeoNames code page mentioned before. It is called geonames_desc.csv and you an access it from the supplementary material's ch03 folder or download it directly from https://gaborfarkas.github.io/practical_gis/ch03/geonames_desc.csv ...