給定一個節點,我想查詢該節點的任何傳入關係並返回具有該關係的節點。我正在修改Node Neoj4 Template如何從Node.js中的Cypher查詢檢索非空白對象
我期待收回節點數組,爲每個元素創建對象,然後引用節點屬性。相反,我找回空物體。然而,我確實得到了正確的查詢節點數(即2個入站關係,返回2個元素)。
我已經在cypher shell中運行了查詢,並得到了我期望的結果。我正在使用Neo4j 1.9.2
關於圖表: 我有一個由8個People節點和2個關係類型組成的族譜圖:INHERITS_X,INHERITS_Y。這是指決定性別的染色體。例如,如果我有兩個孩子,那麼我有兩個傳入關係;我的兒子INHERITS_Y和我的女兒INHERITS_X。
任何幫助表示讚賞。
謝謝,
這裏就是查詢功能(getInbound)被調用:
exports.show = function (req, res, next) {
Person.get(req.params.id, function (err, person) {
if (err) return next(err);
person.getInbound(function (err, inbound) {
res.render('person', {
person: person
})
})
})
};
而且getInbound功能:
Express server listening on port 5000
GET /persons 304 77ms
IN getInbound - this.name is Eddie Dickey
Error from the query null
results length returned from query: 2
In the for loop, var i = 0
Creating a new Person object form each element of array returned from query { _node: { m: { db: [Object], _request: [Object], _data: [Object] } } }
In the for loop, var i = 1
Creating a new Person object form each element of array returned from query { _node: { m: { db: [Object], _request: [Object], _data: [Object] } } } GET /persons/0 200 21ms - 602b
而人的構造函數:從運行代碼
Person.prototype.getInbound = function(callback) {
var query = ['START p=node({ID})',
'MATCH p <-[:INHERITS_Y|INHERITS_X]- m',
'RETURN m'
].join('\n');
var params = {
ID: this.id,
NAME: this.name
};
console.log("In getInbound function");
console.log("this.name is ",this.name);
var in_nodes = [];
db.query(query, params, function (err, results) {
console.log("Error from the query ",err);
if (err) return callback(err);
console.log("Number of elements in array returned from query: ", results.length);
for (var i=0; i< results.length; i++) {
console.log(" In the for loop, var i = ",i);
var in_node = new Person(results[i]);
console.log("New Person object created from array element ", in_node);
in_nodes.push(in_node);
}
callback(null, in_nodes);
});
};
輸出
var Person = module.exports = function Person(_node) {
// all we'll really store is the node; the rest of our properties will be
// derivable or just pass-through properties (see below).
this._node = _node;
}
順便說一下,從每個結果中「拔除」m節點很容易通過ES5的Array.prototype.map來完成,例如, 'results.map(function(res){return res ['m'];})'。使用Underscore.js更簡單:'_(results).pluck('m')'。 (http://underscorejs.org/#pluck) –
啊哈!我知道我錯過了一些基本的東西。現在就像魅力一樣。非常感謝您回答並創建模板應用程序! –