如何正确调用apoc.map.groupBy()？

Question

当我调用这个时：

MATCH (node:Wallet)
WITH collect(node) AS nodes
CALL apoc.algo.pageRankWithConfig(nodes,{types:'SendTo'}) YIELD node, score
WITH nodes, collect({id:toString(id(node)),score:score}) as ranks
call apoc.map.groupBy(ranks,'id') as ranksById
CALL apoc.algo.closeness(['SendTo'],nodes,'INCOMING') YIELD node, score
RETURN node, ranksById[toString(id(node))] as rank, score

抛出此错误：

Invalid input 'a': expected whitespace, comment, result fields of a procedure, LOAD CSV, START, MATCH, UNWIND, MERGE, CREATE, SET, DELETE, REMOVE, FOREACH, WITH, CALL, RETURN, UNION, ';' or end of input (line 5, column 35 (offset: 224))
"call apoc.map.groupBy(ranks,'id') as ranksById"
                                   ^

当我尝试这样调用它时：

MATCH (node:Wallet)
WITH collect(node) AS nodes
CALL apoc.algo.pageRankWithConfig(nodes,{types:'SendTo'}) YIELD node, score
WITH nodes, collect({id:toString(id(node)),score:score}) as ranks
call apoc.map.groupBy(ranks,'id') YIELD values
CALL apoc.algo.closeness(['SendTo'],nodes,'INCOMING') YIELD node, score
RETURN node, values[toString(id(node))] as rank, score

错误是： There is no procedure with the name `apoc.map.groupBy` registered for this database instance. Please ensure you've spelled the procedure name correctly and that the procedure is properly deployed.

当我用 call apoc.help('apoc.map.groupBy') 检查时，方法已注册，签名为 apoc.map.groupBy(values :: LIST? OF ANY?, key :: STRING?) :: (MAP?)。

如何正确调用apoc.map.groupBy？

Answer 1

这是因为 apoc.map.groupBy() 是一个函数，而不是一个过程。 Neo4j 3.1 引入了自定义用户函数（可以作为表达式内联调用，不需要 CALL 或 YIELD），因此许多过程更改为函数以提高灵活性。

将您的 CALL 行更改为 WITH，如下所示：

WITH nodes, apoc.map.groupBy(ranks,'id') as values
...

如何正确调用apoc.map.groupBy()？

How to call apoc.map.groupBy() correctly?

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