如何使用mongodb获得节点Api的结果
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我正在尝试使用芒果聚合的此节点API，但没有得到一些意外的令牌问题。一些提出意外的令牌问题
const monthsEnum = {
"_id": "year",
"1": "January",
"2": "February",
"3": "March",
"4": "April",
"5": "May",
"6": "June",
"7": "July",
"8": "August",
"9": "September",
"10": "October",
"11": "November",
"12": "December"
};
app.get('/polute', function (req, res) {
Air_pollution.aggregate([
{ "$match": {
"CREATE_DATE": {
"$lte": new Date(),
"$gte": new Date(new Date().setDate(new Date().getDate()-120))
}
} },
{ "$group": {
"_id": {
"month": { "$month": "$CREATE_DATE" },
"year": { "$year": "$CREATE_DATE" }
},
"avgofozone": { "$avg": "$OZONE" }
} },
{ "$group": {
"_id": "$year",
"avgs": {
"$push": {
"k": { "$substr": ["$month", 0, -1 ] },
"v": "$avgofozone"
}
}
} },
{ "$replaceRoot": {
"newRoot": {
"$mergeObjects": [
{ "$arrayToObject": "$avgs" },
"$$ROOT"
]
}
} },
{ "$project": { "avgs": 0 } }
], (err, Air_pollution) => {
console.log("naresh:" +JSON.stringify(Air_pollution));
const polute = Object.keys(Air_pollution).reduce((p, c) => ({...p, monthsEnum[c]: Air_pollution[c]}), {});
res.json(Air_pollution);
}),
expected output:
[
{
"zone_type": "avgofozone",
"year": 2018,
"February": 21.07777777777778,
"March": 17.8,
"January": 17.8
}
]
答案
定义对象时，需要将变量属性名称完全包含在[]中。更改
const polute = Object.keys(Air_pollution)
.reduce((p, c) => ({
...p,
monthsEnum[c]: Air_pollution[c]
}), {});
至
const polute = Object.keys(Air_pollution)
.reduce((p, c) => ({
...p,
[monthsEnum[c]]: Air_pollution[c]
}), {});
我还建议提前定义大型数组，这样你就可以同时看到功能的内容，有点像这样：
const monthsEnum = {
"_id": "year",
"1": "January",
"2": "February",
"3": "March",
"4": "April",
"5": "May",
"6": "June",
"7": "July",
"8": "August",
"9": "September",
"10": "October",
"11": "November",
"12": "December"
};
const arr = [{
"$match": {
"CREATE_DATE": {
"$lte": new Date(),
"$gte": new Date(new Date().setDate(new Date().getDate() - 120))
}
}
},
{
"$group": {
"_id": {
"month": {
"$month": "$CREATE_DATE"
},
"year": {
"$year": "$CREATE_DATE"
}
},
"avgofozone": {
"$avg": "$OZONE"
}
}
},
{
"$group": {
"_id": "$year",
"avgs": {
"$push": {
"k": {
"$substr": ["$month", 0, -1]
},
"v": "$avgofozone"
}
}
}
},
{
"$replaceRoot": {
"newRoot": {
"$mergeObjects": [{
"$arrayToObject": "$avgs"
},
"$$ROOT"
]
}
}
},
{
"$project": {
"avgs": 0
}
}
];
app.get('/polute', function(req, res) {
Air_pollution.aggregate(arr, (err, Air_pollution) => {
console.log("naresh:" + JSON.stringify(Air_pollution));
const polute = Object.keys(Air_pollution)
.reduce((p, c) => ({
...p,
[monthsEnum[c]]: Air_pollution[c]
}), {});
res.json(Air_pollution);
})
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