Question

I am new to MySql and sql.
i can’t figure out how to do the following:

i have a bus schedule database with four relevant tables:

stops (24,403 rows)
-------------------
stop_id   int(11)


stopTimes (12,073,459 rows)
---------------------------
trip_id         varchar(30)
stop_sequence   int(11)     // running sequence within the trip: 1-last
stop_id         int(11)

trips (320,395 rows) 
---------------------------
trip_id   varchar(30)
route_id  int(11)


routes (9,748 rows)
---------------------------
route_id            int(11)
agency_id           int(11)                     
route_short_name    varchar(10)

relations

• routes to trips: one to many
• trips to stopTimes: one to many
• stops to stopTimes: one to one

out of these tables i would like to create a new table “routeStops” with the following fields:

routeStops (~100,000 rows)
---------------------------
route_id            int(11)
agency_id           int(11)                     
route_short_name    varchar(10)
stop_id   int(11)

with a one to many relationship between it and the stops.

is there an SQL query that can perform that?

should i add an index to the route_id and stop_id to optimize performance? should i add a fulltext index to trip_id?

i am new to that and will appreciate some insights.

i am using PHPMyAdmin and a rather new XAMPP installation.

tnx,

Answer 1

Is there an SQL query that can perform that?

You can achieve it using the INSERT … SELECT syntax:

INSERT INTO routeStops (route_id, agency_id, route_short_name, stop_id)
SELECT DISTINCT r.route_id, r.agency_id, r.route_short_name, s.stop_id
  FROM routes r
  JOIN trips t ON r.route_id = t.route_id
  JOIN stopTimes s ON t.trip_id = s.trip_id;

Should I add an index to the route_id and stop_id to optimize performance?

Those should be the primary key in their tables, and a foreign key in the other tables.

Should I add a fulltext index to trip_id?

I don’t recommend it because it would be too slow. I suggest that you alter your tables and use an int for the trip_id:

CREATE TABLE trips (
  trip_id int(10) unsigned NOT NULL,
  trip_id_old varchar(30) DEFAULT NULL,
  route_id int(11) DEFAULT NULL,
  PRIMARY KEY (trip_id)
)