CREATE DATABASE Favourite_colours;
CREATE TABLE my_table(
id serial NOT NULL PRIMARY KEY,
colour_1 VARCHAR,
colour_2 VARCHAR
);
INSERT INTO my_table(colour_1, colour_2)
VALUES
('red', 'red'),
('red', 'red'),
('red', NULL),
(NULL, 'red'),
('red', 'green'),
('red', 'blue'),
('green', 'red'),
('green', 'blue'),
('green', 'green'),
('blue', 'red'),
('blue', 'green'),
('blue', 'blue');
SELECT
id,
colour_1,
colour_2
FROM
my_table;