假设我有一个包含电影演员姓名和他们去过的电影的非标准化表格。例如。
CREATE TABLE movies_actors (
movies_actors_id INT,
movie VARCHAR(255),
actor VARCHAR(255),
PRIMARY KEY (movies_actors_id)
);
我会SELECT actor, COUNT(1) FROM movies_actors GROUP BY actor
查明该演员参演了多少部电影。但我也想查明该演员参演的电影的百分比。
我想我可以这样做:
SELECT
actor,
COUNT(1) AS total,
COUNT(1) / (SELECT COUNT(1) FROM movies_actors) * 100 AS avg
FROM movies_actors
GROUP BY actor;
但这似乎...... idk...... 恶心。
有任何想法吗?