    SELECT * FROM shirts WHERE article='polo shirt';

    UPDATE shirts SET shirt_size='L' WHERE article='polo shirt';

    SELECT * FROM shirts WHERE article='polo shirt';

    SELECT * FROM shirts;

    SELECT * FROM shirts WHERE last_worn=15;

    UPDATE shirts SET last_worn=0 WHERE last_worn=15;

    SELECT * FROM shirts WHERE last_worn=15;

    SELECT * FROM shirts WHERE last_worn=0;

    SELECT * FROM shirts WHERE color='white';

    UPDATE shirts SET color='off white', shirt_size='XS' WHERE color='white';

    SELECT * FROM shirts WHERE color='white';

    SELECT * FROM shirts WHERE color='off white';

    SELECT * FROM shirts;