A brief introduction to adding and customizing infowindows on your CartoDB maps. This tutorial will teach you how to add beautiful infowindows to your maps in two minutes with zero coding.
A brief tutorial that will show you how to add, arrange, and edit multiple layers on your maps at the same time.
Use basic spatial SQL to count the number of points that are inside polygons. The tutorial uses two tables, one containing polygons and the second containing points.
UPDATE polygon_table SET point_count = (SELECT count(*) FROM points_table WHERE ST_Intersects(points_table.the_geom, polygon_table.the_geom))
PostGIS ST_Intersects Documentation
In this tutorial you can see how to quickly add and edit geometries in CartoDB. You can add points or draw new linestrings and polygons directly from map view.
Use a small bit of SQL to turn points into circles of specific center and radius.
First SQL used
UPDATE table_name SET the_geom = ST_Buffer(the_geom::geography, 100000)::geometry
Second SQL used
UPDATE table_name SET the_geom = ST_Buffer(the_geom::geography, 100000)::geometry WHERE name = 'Frankfurt'
PostgreSQL UPDATE documentation
PostGIS ST_Buffer documentation