mysql连接查询

CREATE TABLE person (
    id INT,
    name VARCHAR(20),
    cardId INT
);
INSERT INTO person VALUES (1, '小炮', 1);
INSERT INTO person VALUES (2, '幺儿', 3);
INSERT INTO person VALUES (3, '阿鸡', 6);


CREATE TABLE card (
    id INT,
    name VARCHAR(20)
);
INSERT INTO card VALUES (1, '柠檬会员')
INSERT INTO card VALUES (2, '悠悠会员')
INSERT INTO card VALUES (3, '正阳会员')
INSERT INTO card VALUES (4, '霞光会员')
INSERT INTO card VALUES (5, '晨曦会员')

SELECT * FROM person INNER JOIN card ON person.cardId=card.id

SELECT * FROM person LEFT JOIN card on person.cardId=card.id

SELECT * FROM person RIGHT JOIN card on person.cardId=card.id

SELECT * FROM person LEFT JOIN card on person.cardId=card.id
UNION
SELECT * FROM person RIGHT JOIN card on person.cardId=card.id