Question

我有以下查询来获得一个计算喜欢数量的帖子：

MATCH (user:User)-[:CREATED]->(post:Post)
WHERE post.uuid = {postUUID}
RETURN post,
       user.username AS `createdBy`,
       size((post)<-[:LIKES]-(:User)) AS `likes`

我需要的是单独计算每个帖子的喜欢数量。

我当前的查询如下：

MATCH (user:User)-[:CREATED]->(posts:Post)
RETURN posts, user.username AS `createdBy`
ORDER BY posts.createdAt DESC
SKIP {skip}
LIMIT {limit}

谢谢！

Answer 1

如果要返回特定帖子列表的结果（在postUUIDs参数中传递列表）：

MATCH (user:User)-[:CREATED]->(post:Post)
WHERE post.uuid IN {postUUIDs}
RETURN
  post,
  user.username AS `createdBy`,
  size((post)<-[:LIKES]-(:User)) AS `likes`

Answer 2

您可以使用简单聚合：

MATCH (user:User)-[:CREATED]->(post:Post)<-[L:LIKES]-(:User)
WHERE post.uuid = {postUUID}
RETURN user.username AS `createdBy`,
       post,
       count(L) as countOfLikes

Answer 3

您需要重新排序查询，以便首先获得相关的帖子子集，然后对该子集执行其他匹配和计数操作。这样可以避免在首先甚至不返回的节点上执行操作。

.ts

计算每个帖子的喜欢数量

3 个答案: