ALTER TABLE

The table games shows the year and the city hosting the Olympic Games.

games
yr	city
2004	Athens
2006	Turin

schema:scott

 DROP TABLE games

 CREATE TABLE games(
  yr INTEGER PRIMARY KEY,
  city VARCHAR(20));
INSERT INTO games VALUES (2004,'Athens');
INSERT INTO games VALUES (2006,'Turin');

The ALTER statement can be used to add a column. In this example the column season indicates if the games are winter or summer games.

SELECT * FROM scott.games;
ALTER TABLE games ADD season VARCHAR(6);
UPDATE games SET season = 'summer'
  WHERE yr = 2004;
UPDATE games SET season = 'winter'
  WHERE yr = 2006;
SELECT * FROM scott.games;

SELECT * FROM games;
ALTER TABLE games ADD season VARCHAR(6);
UPDATE games SET season = 'summer'
  WHERE yr = 2004;
UPDATE games SET season = 'winter'
  WHERE yr = 2006;
SELECT * FROM games;