combine 4 queries into one

[naroliya]

hi friends,

it should be simple though but i dont know how to do it...

i have the following 4 queries:

select pk_id as touristplaces from city_tourist_places ctp where ctp.city_id=2

select cti.pk_id as traininfo from city_train_info cti where cti.city_id=2

select cfi.pk_id as flightinfo from city_flight_info cfi where cfi.city_id=2

select restaurant_id as restaurant from city_restaurant cr where cr.city_id=2

i want to write only one single query.

im only checking if a record exist for the specific city_id in all the above queries, please note city_id is exist in all tables.

im using mysql 4.1.12.

regards
sanjeev

[chazzy]

use the union keyword.