Queries with the same semantics return different results

[Dong148]

MATCH (u:`user`)-[:watched]->(m:`movie`) WHERE id(u) == "u_100001667" 
WITH collect(id(m)) AS watched_movies_id  
MATCH (u:`user`)-[e:watched]->(m:`movie`)-[:directed_by|acted_by|with_genre]->(intersection)<-[:directed_by|acted_by|with_genre]-(recomm:`movie`) 
WHERE id(u) == "u_100001667" AND NOT id(recomm) IN watched_movies_id 
RETURN DISTINCT recomm

返回了7424条结果，而

GO FROM "u_100001667" OVER watched YIELD dst(edge) as watched_movies_id | 
GO FROM $-.watched_movies_id OVER * YIELD src(edge) as watched_movies_id,dst(edge) as des | 
GO FROM $-.des OVER * REVERSELY WHERE src(edge) != $-.watched_movies_id YIELD DISTINCT src(edge) as recomm

和

MATCH (u:`user`)-[:watched]->(m:`movie`) WHERE id(u) == "u_100001667" 
WITH m,collect(id(m)) AS watched_movies_id  
MATCH (m:`movie`)-[:directed_by|acted_by|with_genre]->(intersection)<-[:directed_by|acted_by|with_genre]-(recomm:`movie`) 
WHERE NOT id(recomm) IN watched_movies_id 
RETURN DISTINCT recomm

都返回了7430条结果

我觉得这几条语句应该都是一样的，从user u_100001667 出发，经过6个他看过的电影找到所有和他看过的电影同分类的并且没看过的电影；
我写错了吗，请问他们有啥区别呢

[Dong148]

GO FROM "u_100001667" OVER watched YIELD dst(edge) as watched_movies_id | 
GO FROM $-.watched_movies_id OVER * YIELD src(edge) as watched_movies_id,dst(edge) as des | 
GROUP BY $-.des YIELD collect($-.watched_movies_id) as watched_movies_id,$-.des as des| 
GO FROM $-.des OVER * REVERSELY WHERE NOT src(edge) IN $-.watched_movies_id YIELD DISTINCT src(edge) as recomm

似乎原来的语句里面WHERE没有发挥作用，这样改写之后返回的结果是7424

[yixinglu]

先说两个 MATCH 之间的差异点：WITH m, collect(id(m)) AS watched_movies_id，这句 with 表示的是按照变量 m 做分组，所以这里的 watched_movies_id 也就只有一个电影的 id，第二句 match 表示的只是推荐的电影不能跟当前电影是同一部电影，这个跟第一句的 match 语意不同。

同样两句 GO 差不多也是上述的差异

[QingZ11]

@Dong148 这个 issue 超过一个月没有更新内容了，这边先行关闭了。如果你有任何更新的内容，可以再打开这个 issue。

谢谢你的反馈 😊