1050. 合作过至少三次的演员和导演

发表于 更新于

难度系数： 简单
ActorDirector 表：

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+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| actor_id    | int     |
| director_id | int     |
| timestamp   | int     |
+-------------+---------+
timestamp 是这张表的主键.

写一条SQL查询语句获取合作过至少三次的演员和导演的 id 对 (actor_id, director_id)

示例：

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ActorDirector 表：
+-------------+-------------+-------------+
| actor_id    | director_id | timestamp   |
+-------------+-------------+-------------+
| 1           | 1           | 0           |
| 1           | 1           | 1           |
| 1           | 1           | 2           |
| 1           | 2           | 3           |
| 1           | 2           | 4           |
| 2           | 1           | 5           |
| 2           | 1           | 6           |
+-------------+-------------+-------------+

Result 表：
+-------------+-------------+
| actor_id    | director_id |
+-------------+-------------+
| 1           | 1           |
+-------------+-------------+
唯一的 id 对是 (1, 1)，他们恰好合作了 3 次。

SQL结构

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Create table If Not Exists ActorDirector (actor_id int, director_id int, timestamp int);
Truncate table ActorDirector;
insert into ActorDirector (actor_id, director_id, timestamp) values ('1', '1', '0');
insert into ActorDirector (actor_id, director_id, timestamp) values ('1', '1', '1');
insert into ActorDirector (actor_id, director_id, timestamp) values ('1', '1', '2');
insert into ActorDirector (actor_id, director_id, timestamp) values ('1', '2', '3');
insert into ActorDirector (actor_id, director_id, timestamp) values ('1', '2', '4');
insert into ActorDirector (actor_id, director_id, timestamp) values ('2', '1', '5');
insert into ActorDirector (actor_id, director_id, timestamp) values ('2', '1', '6');

解法1：

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SELECT a.actor_id, director_id
FROM (
SELECT actor_id, director_id, COUNT(timestamp) as corp_count
FROM ActorDirector 
GROUP BY actor_id , director_id) a
WHERE a.corp_count >= 3;

解法2：

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SELECT actor_id, director_id
FROM actordirector
GROUP BY actor_id, director_id
HAVING count(timestamp) >= 3;

原题链接：https://leetcode.cn/problems/actors-and-directors-who-cooperated-at-least-three-times