收集不同的節點，關係多行

Question

我正在寫一個查詢，以便從多條路徑檢索節點和關係：

MATCH path=(p:Label)-[*..100]->() 
RETURN [n in nodes(path) | ID(n)] as nodeIds, 
     [n in nodes(path)] as nodes, 
     [r in relationships(path) | ID(r)] as relationshipIds, 
     [r in relationships(path) | type(r)] as relationshipTypes, 
     [r in relationships(path)] as relationships 

但是我有多個行（對應於每個路徑），以可能是相同的數據。

我想有一個包含所有不同nodeIds，relationshipIds，...

謝謝一行！

Answer 1

當我運行這個查詢時，我沒有得到重複的數據。但我可以看到爲什麼你會認爲有重複的數據。首先，你可以試試這個：

MATCH path=(p:Label)-[*..100]->() 
WITH DISTINCT(path) as path 
RETURN [n in nodes(path) | ID(n)] as nodeIds, 
     [n in nodes(path)] as nodes, 
     [r in relationships(path) | ID(r)] as relationshipIds, 
     [r in relationships(path) | type(r)] as relationshipTypes, 
     [r in relationships(path)] as relationships 
ORDER BY length(path) LIMIT 1; 

這將確保所有路徑都不同，這將意味着你不可能重複的數據，但我認爲這應該已經是這樣的。按路徑長度排序意味着最長的路徑先行，而限制1意味着最長的路徑。

無論如何，您可能看到的重複是由於路徑和路徑片段。假設我有a->b->c。您的查詢將報告三條路徑：

• a->b->c
• a->b
• b->c

注意這是正確的答案。但就節點ID和關係ID而言，您會在結果集中看到大量重複，因爲每個節點ID在結果中至少會出現兩次。