本文介绍了Mongodb聚合查询对累积值进行减法和分组的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
{
"_id" : ObjectId("58f5a22d22679039176d2ee8"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:01:01.000+05:30"),
"Utilization" : NumberInt("63654480"),
"RunStatus" : NumberInt("1"),
"ProductsCount" : NumberInt("681350")
},
{
"_id" : ObjectId("58f5a22d22679039176d2ee9"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:02:02.000+05:30"),
"Utilization" : NumberInt("63655480"),
"RunStatus" : NumberInt("1"),
"ProductsCount" : NumberInt("681370")
},
{
"_id" : ObjectId("58f5a22d22679039176d2eea"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:03:02.000+05:30"),
"Utilization" : NumberInt("63656480"),
"RunStatus" : NumberInt("0"),
"ProductsCount" : NumberInt("681390")
},
{
"_id" : ObjectId("58f5a22d22679039176d2eeb"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:04:02.000+05:30"),
"Utilization" : NumberInt("63657480"),
"RunStatus" : NumberInt("1"),
"ProductsCount" : NumberInt("681420")
},
{
"_id" : ObjectId("58f5a22d22679039176d2eec"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:05:02.000+05:30"),
"Utilization" : NumberInt("63658480"),
"RunStatus" : NumberInt("1"),
"ProductsCount" : NumberInt("681450"),
},
{
"_id" : ObjectId("58f5a22d22679039176d2eed"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:06:02.000+05:30"),
"Utilization" : NumberInt("63659480"),
"RunStatus" : NumberInt("1"),
"ProductsCount" : NumberInt("681470")
},
{
"_id" : ObjectId("58f5a22d22679039176d2eee"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:07:02.000+05:30"),
"Utilization" : NumberInt("63659780"),
"RunStatus" : NumberInt("0"),
"ProductsCount" : NumberInt("681490")
},
{
"_id" : ObjectId("58f5a22d22679039176d2eef"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:08:03.000+05:30"),
"Utilization" : NumberInt("63659880"),
"RunStatus" : NumberInt("1"),
"ProductsCount" : NumberInt("681525")
},
{
"_id" : ObjectId("58f5a22d22679039176d2ef0"),
"MachineID" : NumberInt("1001"),
"Timestamp" : ISODate("2017-04-18T07:09:03.000+05:30"),
"Utilization" : NumberInt("63659980"),
"RunStatus" : ("0"),
"ProductsCount" : NumberInt("681563")
}
从上述集合中，Utilization 和 ProductsCount 是累积值，并且随时间递增.
From the above collection, Utilization and ProductsCount are cumulative values and incremental over time.
需要减去当前行的Utilization和下一行的Utilization，按升序排列.以及基于 RunStatus 的 ProductsCount 的相同操作.
Need to subtract Utilization of current row with Utilization of next row which is sorted in ascending order. As well as same operation for ProductsCount based on RunStatus.
如果当前行的RunStatus为1，下一行为0，则Utilization和ProductsCount的差异应该映射到RunStatus 为 0.
If RunStatus of current row is 1 and next row is 0, then the difference in Utilization and ProductsCount should be mapped to RunStatus of next row which is 0.
然后根据MachineID和RunStatus
预期结果
/* 1 */
{
"MachineID" : 1001,
"RunStatus" : 1,
"Utilization" : 4100,
"ProducedCount" : 135
},
/* 2 */
{
"MachineID" : NumberInt("1001"),
"RunStatus" : NumberInt("0"),
"Utilization" : 1400,
"ProducedCount" : 78
}
聚合框架需要结果.请帮忙.
这是我试过的，
db.collection.aggregate([
{ "$match" : { "$and" : [ { "MachineID" : { "$in" : [ 1001]}} ,
{ "Timestamp" : { "$gte" : ISODate("2017-04-18T01:30:00.000Z"),
"$lte" : ISODate("2017-04-19T01:30:00.000Z")}},]}
},
{
"$addFields": {"lastUtilization": 0}
},
{
"$addFields": {"lastProductsCount" : 0}
},
{
"$group": {
"_id":
{
MachineID : '$MachineID',
"RunStatus": "$RunStatus"
},
"Utilization" :
{
"$sum" :
{
"$cond": [
{ "$ne": [ "$lastUtilization", 0 ] },
{"$subtract" : ["$Utilization",
"$lastUtilization"]}, 0
]
}
},
"ProductsCount" :
{
"$sum" :
{
"$cond": [
{ "$ne": [ "$lastProductsCount", 0 ] },
{"$subtract" : ["$ProductsCount",
"$lastProductsCount"]}, 0
]
}
},
"lastProductsCount" : { "$avg" : "$ProductsCount"},
"lastUtilization" : { "$avg" : "$Utilization"}
}
},
{
"$project":
{
"MachineID": "$_id.MachineID",
"RunStatus" : "$_id.RunStatus",
"Utilization" : "$Utilization",
"ProductsCount" : "$ProductsCount"
}
},
]);
推荐答案
怎么样?它不计算小时，但它会做其他所有事情.
How's this? It doesn't compute the hour, but it does everything else.
[
{
$match: {
$and: [
{MachineID: {$in: [1001]}},
{
Timestamp: {
$gte: ISODate("2017-04-18T01:30:00.000Z"),
$lte: ISODate("2017-04-19T01:30:00.000Z")
}
}
]
}
},
// Add all data to one array.
{$group: {_id: "$MachineID", all: {$push: "$$ROOT"}}},
// Create an array of (element, array index) pairs.
{$addFields: {allWithIndex: {$zip: {inputs: ["$all", {$range: [0, {$size: "$all"}]}]}}}},
// Create an array of {current: <element>, previous: <previous element>} pairs.
{
$project: {
pairs: {
$map: {
input: "$allWithIndex",
in : {
current: {$arrayElemAt: ["$$this", 0]},
prev: {
$arrayElemAt: [
"$all",
// Set prev == current for the first element.
{$max: [0, {$subtract: [{$arrayElemAt: ["$$this", 1]}, 1]}]}
]
}
}
}
}
}
},
// Compute the deltas.
{$unwind: "$pairs"},
{
$group: {
_id: {MachineID: "$_id", RunStatus: "$pairs.current.RunStatus"},
ProductsCount:
{$sum: {$subtract: ["$pairs.current.ProductsCount", "$pairs.prev.ProductsCount"]}},
Utilization:
{$sum: {$subtract: ["$pairs.current.Utilization", "$pairs.prev.Utilization"]}},
}
}
]
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