SQL - 选择不同的行并将它们与另一个表连接以获取数据

Question

我有两张桌子：

1）person（person_id，person_name）

2）汽车（car_id，person_id）

我想得到所有人的名字都没有重复的汽车。

这就是我的想法：

SELECT person.person_name, cars.person_id
FROM cars
INNER JOIN person
ON person.person_id=cars.person_id

但我不想要重复，所以我需要使用类似的东西来加入它：

SELECT DISTINCT person_id FROM cars

Answer 1

select person_name from person
where person_id in ( select person_id from cars )

Answer 2

SELECT DISTINCT person.person_name, person.person_id
FROM cars
INNER JOIN person
ON person.person_id=cars.person_id

虽然可能有更多高性能的替代品。

Answer 3

试试这个：

SELECT  p.person_id, p.person_name
   FROM  person p
WHERE     EXISTS
(
    SELECT 1
      FROM cars c
    WHERE c.person_id = p.person_id
)

Answer 4

SELECT p.person_id AS person_id, p.name AS name FROM person p, cars c    
WHERE p.person_id = c.person_id    
GROUP BY b.brand_id

Answer 5

SELECT DISTINCT(person.person_name) 
FROM person, cars 
WHERE person.person_id = cars.person_id