我希望在 MongoDB 聚合中找到的平均值得出一个综合值
[
{
"_id": "581c3d9c55421c16ecaf0b26",
"uDept": "CoE Design & Research",
"uName": "Saurabh Raman",
"rateVal": 3,
"timeStamp": "11/4/2016 13:17",
"__v": 0
},
{
"_id": "581c437ea3d9f6087ce3b21e",
"uDept": "CoE Design & Research",
"uName": "Sachin P Singh",
"rateVal": 4,
"timeStamp": "11/4/2016 13:42",
"__v": 0
},
{
"_id": "581c6d74a3d9f6087ce3b21f",
"uDept": "Training",
"uName": "Rahul Shakya",
"rateVal": 4,
"timeStamp": "11/4/2016 16:35",
"__v": 0
}
]
我运行以获取“rateVal”平均值的查询
db.calcR.aggregate([
{
$group: {
_id: null,
avg: {$avg: '$rateVal'},
}
}
输出为
{ avg: 3.6666 }但理想情况下我希望它显示为 4[
{
"_id": null,
"avg": 3.6666666666666665,
}
]
最佳答案
要舍入 mongoDb 中的值，您可以使用 $ceil或 $floor
db.calcR.aggregate([
{
$group: {
_id: null,
avg: {$avg: '$rateVal'},
},
$project:{
_id: '$_id' ,
roundedAvg : { $ceil: '$avg' }
}
}]
输出看起来像
[
{
"_id": null,
"roundedAvg": 4,
}
]
关于mongodb - 综合平均值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40459844/