我有这样的数据
"delivery": [{
"status": "Not Started",
"createdAt": {
"$date": "2020-12-21T03:50:33.877Z"
},
"updatedAt": {
"$date": "2020-12-21T03:50:33.877Z"
}
}, {
"status": "Accepted",
"updatedAt": {
"$date": "2020-12-21T03:51:20.915Z"
},
"createdAt": {
"$date": "2020-12-21T03:51:20.915Z"
}
}, {
"status": "Ongoing",
"updatedAt": {
"$date": "2020-12-21T03:52:40.087Z"
},
"createdAt": {
"$date": "2020-12-21T03:52:40.087Z"
}
}, {
"status": "Ended",
"updatedAt": {
"$date": "2020-12-21T03:52:40.087Z"
},
"createdAt": {
"$date": "2020-12-21T04:00:40.087Z"
}
我想获取从Not Started到Accepted以及从Ongoing到Ended的时间差。我遇到错误cant $subtract aarray from a array我希望得到两个不同数组之间的差异。
db.deliveries.aggregate([
{
$project:
{
"delivery.createdAt": 1,
"delivery.updatedAt": 1
}
},
{
$addFields: {
difference: {
$divide: [{$subtract: ["$delivery.updatedAt", "$delivery.createdAt"]}, 3600000]
}
}
},
])
预期输出:
{
"status": "Not Started",
"createdAt": {
"$date": "2020-12-21T03:50:33.877Z"
},
"updatedAt": {
"$date": "2020-12-21T03:50:33.877Z"
}
}, {
"status": "Accepted",
"updatedAt": {
"$date": "2020-12-21T03:51:20.915Z"
},
"createdAt": {
"$date": "2020-12-21T03:51:20.915Z"
}
},
difference: 0.013066111111111112
{
"status": "Ongoing",
"updatedAt": {
"$date": "2020-12-21T03:52:40.087Z"
},
"createdAt": {
"$date": "2020-12-21T03:52:40.087Z"
}
}, {
"status": "Ended",
"updatedAt": {
"$date": "2020-12-21T03:52:40.087Z"
},
"createdAt": {
"$date": "2020-12-21T04:00:40.087Z"
},
difference: 0.08 //sample computation
我想计算从 Not Started(createdAt) 到 Accepted(updatedAt) 的差异。并获得从 **Ongoing(createdAt) 到 Ended(updatedAt) 的差异。
您可以通过 $addFields 和 $cond 来找出开始和结束时间。然后计算差异,
db.collection.aggregate([
{
"$addFields": {
"start": {
"$reduce": {
"input": "$delivery",
"initialValue": null,
"in": {
"$cond": {
"if": {
$eq: [
"$$this.status",
"Not Started"
]
},
"then": "$$this.createdAt",
"else": "$$value"
}
}
}
},
"end": {
"$reduce": {
"input": "$delivery",
"initialValue": null,
"in": {
"$cond": {
"if": {
$eq: [
"$$this.status",
"Accepted"
]
},
"then": "$$this.updatedAt",
"else": "$$value"
}
}
}
}
}
},
{
"$addFields": {
"difference": {
"$divide": [
{
"$subtract": [
"$end",
"$start"
]
},
3600000
]
}
}
}
])
这里是Mongo Playground供您参考。