Neo4j 密码查询 : Parenthesis not considered in WHERE clause?

Question

我正在尝试运行如下查询:

MATCH (n:Type1)-[:relation1]->(:Type1)<-[:relation2]-(:Type2) WHERE
((n.prop1="A" and n.prop2 in [42, 34]) OR
 (n.prop1="B" and n.prop2 in [67])     OR
 (n.prop1="C" and n.prop2 in [51, 43]) OR
 (n.prop1="D" and n.prop2 in [56, 42])) 
RETURN DISTINCT id(n) as node_id, n.prop3 as node_prop3, n.prop1 as prop1, n.prop2 as prop2;

这给出了混合结果，即 prop1="D" 与 prop2=51 匹配，这显然不符合预期条件。就好像括号在条件的形成中没有发言权。当我在 WHERE 子句中运行不带括号的查询时，结果是相同的。

虽然，如果我查询类似:

MATCH (n:Type1)-[:relation1]->(:Type1)<-[:relation2]-(:Type2) WHERE
((n.prop1="A" and n.prop2=42) OR
 (n.prop1="A" and n.prop2=34) OR
 (n.prop1="B" and n.prop2=67) OR
 (n.prop1="C" and n.prop2=51) OR
 (n.prop1="C" and n.prop2=43) OR
 (n.prop1="D" and n.prop2=56) OR
 (n.prop1="D" and n.prop2=42)) 
RETURN DISTINCT id(n) as node_id, n.prop3 as node_prop3, n.prop1 as prop1, n.prop2 as prop2;

在将示例 2 中的单独条件替换为示例 1 中的 IN 以避免对 prop1 进行重复字符串比较时，我是否遗漏了什么？

Answer 1

我相信 IN 会按您的预期工作。

设置示例数据。

(:Type1 {prop1:"A", prop2:34}),
(:Type1 {prop1:"B", prop2:67}),
(:Type1 {prop1:"C", prop2:51}),
(:Type1 {prop1:"C", prop2:43}),
(:Type1 {prop1:"D", prop2:56}),
(:Type1 {prop1:"D", prop2:42}),
(:Type1 {prop1:"D", prop2:51}),
(:Type1 {prop1:"B", prop2:42});

MATCH (t:Type1)
MERGE (t)-[:relation1]->(:Type1)<-[:relation2]-(:Type2);

现在运行您的查询。

MATCH (n:Type1)-[:relation1]->(:Type1)<-[:relation2]-(:Type2) WHERE
((n.prop1="A" and n.prop2 in [42, 34]) OR
 (n.prop1="B" and n.prop2 in [67])     OR
 (n.prop1="C" and n.prop2 in [51, 43]) OR
 (n.prop1="D" and n.prop2 in [56, 42])) 
RETURN DISTINCT id(n) as node_id, n.prop3 as node_prop3, n.prop1 as prop1, n.prop2 as prop2;

语句返回7条记录，结果不包含prop1=D，prop2=51的节点。

参见 this answer如果您省略了括号，请参阅有关 bool 运算符优先级的信息。