cheatsheet
https://pbs.twimg.com/media/F3ZhG3xWAAAUpYM.jpg
https://pbs.twimg.com/media/F0_u3qDXsAIBt4j.jpghttps://pbs.twimg.com/media/F0_u4fCWIAImP5-.jpghttps://pbs.twimg.com/media/F0_u5MwWcAEO2kL.jpghttps://pbs.twimg.com/media/F0_u5-1WAAE9B-6.jpg
code:sql
-- A & B
SELECT *
FROM A
INNER JOIN B ON A.key = B.key
-- A || B
SELECT *
FROM A
FULL JOIN B ON A.key = B.key
-- A || B - A & B
SELECT *
FROM A
FULL JOIN B ON A.key = B.key
WHERE A.key IS NULL OR
B.key IS NULL
-- A
SELECT *
FROM A
LEFT JOIN B ON A.key = B.key
-- A || B - B
SELECT *
FROM A
LEFT JOIN B ON A.key = B.key
WHERE B.key IS NULL
-- B
SELECT *
FROM A
RIGHT JOIN B ON A.key = B.key
-- A || B - A
SELECT *
FROM A
RIGHT JOIN B ON A.key = B.key
WHERE B.key IS NULL