Introduction
Points
Linestrings
Polygons
Instruction
Alright. Let's start discussing subtypes of the geometry type. The first types we're going to deal with are points. Each point represents one location on Earth. There are two tables with points in our database, so let's get to know them.
Exercise
Select all the information from the table sf_tram_stops.
As you may recall, there are three columns in this table:
-
id- the unique identifier of each tram stop, coordinates- the location of the tram given as ageometrycolumn,transfer_possible- either true or false; this column indicates whether a passenger can change to other trams at this stop.
Check the map. Notice how stops typically come in pairs, one stop for travel in each direction.
Stuck? Here's a hint!
To select everything, use SELECT *.
