How many short cars are in the shape of hexagon?
short cars refers to len = 'short'; in the shape of hexagon refers to shape = 'hexagon'
SELECT COUNT(id) FROM cars WHERE shape = 'hexagon' AND len = 'short'
database name:db_id trains
cars table cars Cols: id dtype integer, train id dtype integer, position dtype integer, shape dtype text, length dtype text, sides dtype text, roof dtype text, wheels dtype integer, load_shape dtype text, load number dtype integer, 
trains table trains Cols: id dtype integer, direction dtype text, 
