An example of postgres function ( stored procedure ) that returns a query.

pgsql_function_example.sql

CREATE OR REPLACE FUNCTION stored_get_data_history(SPGroupID integer, FromDate timestamp with time zone, ToDate timestamp with time zone) 
RETURNS TABLE (device_id integer, "location" geometry, accuracy DOUBLE PRECISION, speed DOUBLE PRECISION, azimuth DOUBLE PRECISION, "createdAt" timestamp with time zone) LANGUAGE PLPGSQL AS $$
BEGIN
RETURN QUERY SELECT 
	  "Data".device_id, 
	  "Data".location, 
	  "Data".accuracy, 
	  "Data".speed, 
	  "Data".azimuth, 
	  "Data"."createdAt"
	FROM 
	  public."Data", 
	  public."DeviceMemberships"
	WHERE 
	  "DeviceMemberships".device_id = "Data".device_id AND 
	  "DeviceMemberships".group_id = SPGroupID AND
	  "Data"."createdAt" >= FromDate AND
	  "Data"."createdAt" <= ToDate;
END;
$$; 

SELECT * FROM stored_get_data_history(0, '2015-08-29 14:12:17.914+02','2015-08-29 14:50:27.37+02');