SELECT .. JOIN

The SELECT .. JOIN statement

Sometimes you need to access two or more tables to get the data required.

games yr city 1896 Athens 1948 London 2004 Athens 2008 Beijing 2012 London	city name country Sydney Australia Athens Greece Beijing China London UK

schema:scott

DROP TABLE games CASCADE;
DROP TABLE city CASCADE

CREATE TABLE games(
  yr INTEGER,
  city VARCHAR(20));
INSERT INTO games VALUES (1896,'Athens');
INSERT INTO games VALUES (1948,'London');
INSERT INTO games VALUES (2004,'Athens');
INSERT INTO games VALUES (2008,'Beijing');
INSERT INTO games VALUES (2012,'London');
CREATE TABLE city (
   name VARCHAR(20),
   country VARCHAR(20));
INSERT INTO city VALUES ('Sydney','Australia');
INSERT INTO city VALUES ('Athens','Greece');
INSERT INTO city VALUES ('Beijing','China');
INSERT INTO city VALUES ('London','UK');

You can use a JOIN to get results from two or more related tables. In this example each row of the table games is related to a row of the table city. If you want to find the country where the games took place you must JOIN the games table to the city table on the common field that is games.city and city.name

SELECT games.yr, city.country
  FROM scott.games JOIN scott.city
       ON (games.city = city.name)

SELECT games.yr, city.country
  FROM games JOIN city
       ON (games.city = city.name)

See also

• JOIN Tutorial
• Another JOIN Tutorial
• SELECT .. LEFT JOIN