猫鼬-仅按日期部分对日期排序，忽略时间 [英] Mongoose - sort Date by date part only, ignoring time

问题描述

我有一个用于以下模型的收藏集:

const VisitSchema = new mongoose.Schema({
    priority: { type: Number, min: 1, max: 3, required: true },
    datetime: { type: Date, required: true },
    // some other information
});

我正在尝试对所有文档进行排序，以使比当前日期更近的访问显示在后面的访问之前，但是在一天之内，必须首先显示优先级较高的访问.

例如:考虑

A (17-08-2018 14:00:00, P3)

B (17-08-2018 15:00:00, P2)

C (18-08-2018 15:00:00, P1)

在对它进行排序时，所需的响应应该为[B, A, C]，因为在17-08-2018日，即使A更早，并且C具有比A更早的优先级，B也具有比A更高的优先级. A和B，都在以后的一天.

我正在寻找一种方法，该方法首先按datetime进行排序，但仅考虑日期部分并忽略时间，然后再按priority进行排序.我目前的尝试完全考虑了datetime，这给了我错误的排序方式:

Visit.find().sort('datetime priority')

编辑:我知道我可以使用Array.sort()来做到这一点.问题是直接从mongoose执行此操作，而不是先检索数据然后才进行排序.

解决方案

您可以尝试在3.6以下的聚合中进行自定义排序.

使用 $dateFromParts 来计算日期而无需时间 $addFields 可以将计算所得的值保留为该文档后跟 $sort 在字段中排序.

$project ，并排除掉排序字段以获得预期的输出.

db.col.aggregate([
 {"$addFields":{
   "date":{
     "$dateFromParts":{
       "year":{"$year":"$datetime"},
       "month":{"$month":"$datetime"},
       "day":{"$dayOfMonth":"$datetime"}
      }
    }
 }}, 
 {"$sort":{"date":-1,"priority":1}},
 {"$project":{"date":0}}
])

I have a collection for the following model:

const VisitSchema = new mongoose.Schema({
    priority: { type: Number, min: 1, max: 3, required: true },
    datetime: { type: Date, required: true },
    // some other information
});

I'm trying to sort all documents in a way that the Visits closer to current date are shown before the later ones, but within a day, the ones with higher priority must be shown first.

For example: consider

A (17-08-2018 14:00:00, P3)

B (17-08-2018 15:00:00, P2)

C (18-08-2018 15:00:00, P1)

when sorting this, the desired response should be [B, A, C], because on day 17-08-2018, B has higher priority over A even though A is earlier and even if C has higher priority over both A and B, it is on a later day.

I'm looking for a way to sort firstly by datetime, but consider only the Date part and ignoring the Time, and later by priority. My current attempt considers the datetime entirely, giving me the wrong sorting:

Visit.find().sort('datetime priority')

EDIT: I know I can do it using Array.sort(). The question is upon doing it directly from mongoose, instead of retrieving the data and only then sorting.

解决方案

You can try below aggregation in 3.6 for custom sort.

Use $dateFromParts to compute date without time in $addFields to keep the computed value as the extra field in the document followed by $sort sort on field.

$project with exclusion to drop the sort field to get expected output.

db.col.aggregate([
 {"$addFields":{
   "date":{
     "$dateFromParts":{
       "year":{"$year":"$datetime"},
       "month":{"$month":"$datetime"},
       "day":{"$dayOfMonth":"$datetime"}
      }
    }
 }}, 
 {"$sort":{"date":-1,"priority":1}},
 {"$project":{"date":0}}
])

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