Node.js+;Firebase orderByChild不工作
我试图找出这种嵌套排序,但我所做的一切都行不通 以下是我试图订购的数据结构示例:Node.js+;Firebase orderByChild不工作,node.js,firebase,firebase-realtime-database,Node.js,Firebase,Firebase Realtime Database,我试图找出这种嵌套排序,但我所做的一切都行不通 以下是我试图订购的数据结构示例: { "-KV_Lrm_93Agm8kAuXql": { "body": { "Acceleration": "0.0", "Altitude": "11", "Battery": "12.7", "Date": "2016/09/10", "order": 1, "time": "2016-10-19T20:26:32Z"
{
"-KV_Lrm_93Agm8kAuXql": {
"body": {
"Acceleration": "0.0",
"Altitude": "11",
"Battery": "12.7",
"Date": "2016/09/10",
"order": 1,
"time": "2016-10-19T20:26:32Z"
}
},
"-KV_LuTfJ9VrKRHoRWuw": {
"body": {
"Acceleration": "0.0",
"Altitude": "11",
"Battery": "12.7",
"Date": "2016/09/10",
"order": 5,
"time": "2016-10-21T20:26:32Z"
}
},
"-KV_Lx9VABuEB8D3I-i1": {
"body": {
"Acceleration": "0.0",
"Altitude": "11",
"Battery": "12.7",
"Date": "2016/09/10",
"order": 2,
"time": "2016-10-01T20:26:32Z"
}
},
"-KV_LzQOM3rHEKQuwyHQ": {
"body": {
"Acceleration": "0.0",
"Altitude": "11",
"Battery": "12.7",
"Date": "2016/09/10",
"order": 10,
"time": "2016-09-01T20:26:32Z"
}
},
"-KV_M0fdznAbKanHoY91": {
"body": {
"Acceleration": "0.0",
"Altitude": "11",
"Battery": "12.7",
"Date": "2016/09/10",
"order": 6,
"time": "2016-09-20T20:26:32Z"
}
}
}
根据firebase文档(),您可以执行“深度路径查询”。在我的情况下,如果我想按顺序排序,我应该能够做到:
.orderByChild("body/order")
但这没有任何作用。它对结果的顺序没有影响。我也试过按日期和时间订购,但都没用。这是我的完整节点函数。这将返回结果,只是不按顺序:
app.get('/api/xirgo-data', function(req, res)
{
var ref = db.ref("xirgo");
ref
.orderByChild("body/order")
.on("value", function(snap) {
return res.json(snap.val());
});
});
谢谢 在Firebase中请求查询值时,生成的快照包含匹配子项的键、值和排序信息 但是,当您将其转换为字典/关联数组/JavaScript对象时,由于JavaScript对象本质上是无序的,因此排序信息将丢失 为确保您能够以正确的顺序访问匹配的项目,请使用内置的
DataSnapshot.forEach()
方法:
var ref = db.ref("xirgo");
ref
.orderByChild("body/order")
.on("value", function(snapshot) {
snapshot.forEach(function(child) {
console.log(child.key+': '+child.val());
});
});
完美答案。