CREATE or REPLACE FUNCTION GetNearest(NUMERIC, NUMERIC)
  RETURNS BIGINT AS
  $$
  SELECT id FROM ways_vertices_pgr AS vertices
  ORDER BY vertices.the_geom <-> ST_SetSrid(ST_MakePoint($1, $2), 4326) LIMIT 1;
  $$
LANGUAGE SQL;

INSERT INTO "UserTravelTime" ("FromLat", "FromLng", "ToLat", "ToLng", "Duration", "CreatedOn", "UpdatedOn")
SELECT C1."Lat" AS "FromLat", C1."Lng" AS "FromLng", C2."Lat" AS "ToLat", C2."Lng" "ToLng",
  (SELECT ROUND(SUM(cost)) AS Cost FROM pgr_dijkstra(
    'SELECT gid AS id,
         source,
         target,
         cost_s as cost
        FROM ways',
    (SELECT GetNearest(C1."Lng", C1."Lat")), (SELECT GetNearest(C2."Lng", C2."Lat")),
    directed := true)),
    NOW(),
    NOW()
  FROM
  "UserCoordinate" C1,
  "UserCoordinate" C2;