Question

film_actor，就像这样：

╔═════════╦══════╗
║ film_id ║ Task ║
╠═════════╬══════╣
║    1    ║ 162  ║
║    1    ║ 15   ║
║    1    ║ 20   ║
║    2    ║ 162  ║
║    2    ║ 12   ║
╚═════════╩══════╝

比以下查询：

SELECT film_id
FROM film_actor
WHERE actor_id LIKE '162'

结果：

1
2

下一个查询：

SELECT DISTINCT actor_id
FROM film_actor
WHERE film_id LIKE 'results from the query above'

结果应如下所示：

15
20
12

如何将这两个查询放在一起？第一个的结果不应该显示，它只是最后和最终查询所需要的。

Answer 1

使用IN运算符：

SELECT DISTINCT actor_id
FROM film_actor
WHERE film_id in(SELECT film_id
                 FROM film_actor
                 WHERE actor_id LIKE '162')

或JOIN：

SELECT DISTINCT f2.actor_id
FROM film_actor f1
JOIN film_actor f2 ON f1.film_id = f2.film_id
WHERE f1.actor_id LIKE '162'

Answer 2

SELECT DISTINCT actor_id
FROM film_actor
WHERE film_id IN
(
    SELECT film_id
    FROM film_actor
    WHERE actor_id LIKE '162'
)

Answer 3

多数民众赞成

SELECT DISTINCT actor_id
FROM film_actor
WHERE film_id in (
  SELECT film_id
  FROM film_actor
  WHERE actor_id LIKE '162'
);

Answer 4

你在寻找什么是subquery。你的应该是这样的：

{{1}}

SQL / MYSQL：一个查询中的两个语句

4 个答案: