我有一个运行良好的查询。这给了我所有当前fuelPercentLeft超过50%的列车。
MATCH (t:Train)
WITH t.trainId AS trainid, MAX(t.timestamp) AS maxTimeStamp
MATCH (n:Train{trainId: trainid, timestamp: maxTimeStamp})-[:HAS]->(m:Attributes{name:'fuelPercentLeft'})
WHERE toInteger(m.value) > 50
RETURN count(toInteger(m.value))我只想用一个查询返回多个结果。例如，对于所有的列车，返回fuelPercentLeft大于50、Engine Temperature小于20、Lubricant Level小于10的所有列车。在上面的查询中，是否可以应用多个WHERE条件？我们是否可以执行以下操作？
MATCH (t:Train)
WITH t.trainId AS trainid, MAX(t.timestamp) AS maxTimeStamp
CALL {
MATCH (n:Train{trainId: trainid, timestamp: maxTimeStamp})-[:HAS]->(m:Attributes{name:'fuelPercentLeft'})
WHERE toInteger(m.value) > 50
RETURN count(toInteger(m.value)) AS goodFuel
}
CALL {
MATCH (n:Train{trainId: trainid, timestamp: maxTimeStamp})-[:HAS]->(m:Attributes{name:'fuelPercentLeft'})
WHERE toInteger(m.value) < 50
RETURN count(toInteger(m.value)) AS badFuel
}
CALL {
MATCH (n:Train{trainId: trainid, timestamp: maxTimeStamp})-[:HAS]->(m:Attributes{name:'engineTemp'})
WHERE toInteger(m.value) > 20
RETURN count(toInteger(m.value)) AS goodEngine
}
CALL {
MATCH (n:Train{trainId: trainid, timestamp: maxTimeStamp})-[:HAS]->(m:Attributes{name:'lubricantLevel'})
WHERE toInteger(m.value) < 10
RETURN count(toInteger(m.value)) AS badLubricant
}
RETURN goodFuel, badFuel, goodEngine, badLubricant我试过这个，但它不像预期的那样工作。要求是，一个单一的查询应该能够基于多个条件返回多个值。
请帮忙。谢谢！
2条答案
按热度按时间ztyzrc3y1#
您可以在链中使用可选匹配：
5sxhfpxr2#
您应用了错误的筛选器，对于
trainId和maxTimeStamp，它们不是必需的，请尝试以下操作：