Postgres SQL cheat sheet¶

Official document
https://www.postgresqltutorial.com/postgresql-select/

Nice diagram from dunwu

Union , Except , Intersect¶

Union¶

-- Return only 1 row for duplicate data

SELECT * FROM top_rated_films
UNION
SELECT * FROM most_popular_films;


--  with all duplicate data

SELECT * FROM top_rated_films
UNION ALL
SELECT * FROM most_popular_films;

Except¶

Rows area not in table 2

SELECT * FROM table1
EXCEPT
SELECT * FROM table2;

Intersect¶

SELECT select_list
FROM A
INTERSECT
SELECT select_list
FROM B;