What is the best way to connect spatial data with attributes in Excel table?

Question

I have many attributes which are stored in an Excel table. They refer to USA counties. I need to somehow connect those attributes to polygons in some format (don't know which is the best) and visualize it by Leaflet or similar API. Those attributes need to be in popups.

What do you recommend? How can I connect spatial data (polygons of counties) with attributes stored in Excel table? I'm using software like ArcGIS and Quantum GIS. I am opened to MySQL and PostgreSQL regards to databases if you recommend those.

Please try to explain with more details and exact steps so I can be sure I understand.

Answer 1

If you don't need some kind of routine or script, here is the simple procedere using QGis (Master 1.9, but 1.8 should also work).

• Add your shapefile as vector layer in QGIS
• Add your table (can be .csv or .xls files) to QGis in the same way -> Add Vector Layer
• Both, table and layer should now be visible in the layer table of contents. Now make a simple Join by selecting Join in the Layer properties. Here choose a connecting attribute, which occurs in both datasets (such as the county name or a previously created ID-Number).
• Afterwards your shapes attribute table can easily be exported as .csv or whatever (mmqgis plugin for instance).

Of course there are many more scripted solutions utilizing R, python, Postgis or others possible.

EDIT: Depending on the structure of your dataset (which i don't know) you maybe have to pre process your data first (calculate aggregate means per country, ... )