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我想要得到一個活動列表的關鍵路徑，但通過Neo4j。
爲此，我需要最早的時間（開始和結束）。活動的最早開始等於其前任的最早開始，依此類推。
我已經有一些「工作」。但我的問題是，我只需要「回想起功能」。我可以用手往下走，但我不能這樣做下去......
這裏是我的代碼：
// LEVEL 1
/****** collect (start.successors) as startSucessors *****/
MATCH (project:Project)-[:CONTAINS]->(:Activity{tag:'Start'})-[s:ENABLES]->(:Activity)
WHERE ID(project)=toInteger(322)
WITH collect(endNode(s)) AS startSuccessors
/**** foreach node in startSucessors ****/
UNWIND startSuccessors AS node
/**** collect (node.predecessors) as nodePredecessors ****/
MATCH (activity:Activity)-[p:ENABLES]->(node)
WITH collect(startNode(p)) AS nodePredecessors, node, startSuccessors
/**** foreach activity in nodePredecessors ****/
UNWIND nodePredecessors AS activity
/**** IF (node.ES is null OR node.ES < activity.EF) ****/
WITH node, activity, startSuccessors,(node.ES = 0) AS cond1, (node.ES < activity.EF) AS cond2
MERGE (activity)-[:ENABLES]->(node)
ON MATCH SET node.ES =
CASE
/**if**/ WHEN cond1 OR cond2
/**node.ES = activity.EF**/ THEN activity.EF
END
ON MATCH SET node.EF = node.ES + node.ET
// LEVEL 2
/**T.O.D.O. : loop for each node in startSuccessors and their nodes **/
WITH startSuccessors
UNWIND startSuccessors AS node
MERGE (node)-[s2:ENABLES]->(successor:Activity)
WITH collect(successor) AS nodeSuccessors,node
UNWIND nodeSuccessors AS successor
CREATE UNIQUE (act:Activity)-[p2:ENABLES]->(successor)
WITH successor, node,act, (successor.ES = 0) AS cond3, (successor.ES < act.EF) AS cond4
MERGE (act)-[p2:ENABLES]->(successor)
ON MATCH SET successor.ES =
CASE
/**if**/ WHEN cond3 OR cond4
/**node.ES = activity.EF**/ THEN act.EF
END
ON MATCH SET successor.EF = successor.ES + successor.ET
下面是結果 Earliest Times Query Result
第二個問題是，如果我重新運行查詢，ES和EF屬性消失...（在下面證明）
Problem when rerunning the query
要修復這個問題，我必須運行此查詢：
MATCH (p:Project) WHERE ID(p)=322
MATCH (p)-[:CONTAINS]->(one:Activity{tag:'one'}),(p)-[:CONTAINS]->(zrht:Activity{tag:'zrht'}),(p)-[:CONTAINS]->(ore:Activity{tag:'ore'}),(p)-[:CONTAINS]->(bam:Activity{tag:'bam'}),(p)-[:CONTAINS]->(two:Activity{tag:'two'})
SET one.EF = 0,one.ES = 0,one.LF=0,one.LS=0,zrht.EF = 0,zrht.ES = 0,zrht.LF=0,zrht.LS=0,ore.EF = 0,ore.ES = 0,ore.LF=0,ore.LS=0,bam.EF = 0,bam.ES = 0,bam.LF=0,bam.LS=0,two.EF = 0,two.ES = 0,two.LF=0,two.LS=0
這javascript code達到了我想要做的。
非常感謝您的幫助。