我无法从数据库中获取所需日期的文档。
我的数据库结构是这样的:
{
date: 2019-10-24T10:00:00.000Z,
value: 6
},
{
date: 2019-10-24T10:01:03.000Z,
value: 6
},
{
date: 2019-10-24T10:02:35.000Z,
value: 6
},
...
并尝试获取带有2个参数的查询:
并且每天在startDate和endDate之间传送1个文档,此文档的时间(HH:mm:ss)需要最接近endDate之一。 像这样:
start = new Date('2019-10-22T10:00:00.000Z')
end = new Date('2019-10-24T10:00:00.000Z)
{
date: '2019-10-22T09:59:13.000Z',
value: 10
},
{
date: '2019-10-23T10:00:00.000Z',
value: 17
},
{
date: '2019-10-24T09:58:55.000Z',
value: 10
}
现在,我拥有此汇总函数,可以获取每天的第一份文档:
.aggregate([
{
$match: {
date: { $gte: ISODate('2019-05-26T12:00:00.000Z'), $lte: ISODate('2019-10-26T12:00:00.000Z') }
}
},
{
$project: {
_id: 1,
value: 1,
docDate: '$date',
day: {
'$dayOfMonth': '$date'
},
month: {
'$month': '$date'
},
year: {
'$year': '$date'
}
}
},
{
$project: {
_id: 1,
value: 1,
docDate: 1,
date: {
'$concat': [
{
$substr: ['$year', 0, 4]
},
'-',
{
$substr: ['$month', 0, 2]
},
'-',
{
$substr: ['$day', 0, 2]
}
]
}
}
},
{
$group: {
_id: '$date',
objId: {
$first: '$_id'
},
value: {
$first: '$value'
},
date: {
$first: '$docDate'
}
}
},
{
$project: {
_id: '$objId',
value: 1,
date: 1
}
},
{
'$sort': {
date: 1
}
}
]
)
答案 0 :(得分:2)
所以我认为这个查询可能就是您要寻找的...
const express = require('express');
const fileUpload = require('express-fileupload');
const app = express();
const port = process.env.PORT || 80;
const server = process.env.SERVER || 'pa-dev-1.flanderscapital.com';
const bodyParser = require('body-parser')
// default options
app.use(fileUpload());
// set the view engine to ejs
app.set('view engine', 'ejs');
// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }))
// parse application/json
app.use(bodyParser.json())
app.use(express.static(__dirname + '/public'));
var routes = require('./app/routes')(app);
app.listen(port, server, () => console.log(`PA Tools Server listening on port ${port}!`))
// Get image of GAEA logo
var publicDir = require('path').join(__dirname, 'public');
app.use(express.static(publicDir));
管道策略的分解:
$ match-按日期范围选择要考虑的记录范围
$ addFields-仅获取日期字符串而不带时间。这是$ group实际分组所必需的。如果字符串中也包含时间,则无法正确分组
$ sort date -1 =分组之前需要这样做,因此我们可以在$ group中使用$ first运算符
$ group-汇总并使用$ first选择分组中的项目
$ replaceRoot-将管道输出转回原始文档格式
$ project-删除临时的date_string字段
$ sort date 1-按正常排序顺序放回数据。
输出:
db.records.aggregate([
{ $match: {
date: {
$gte: ISODate('2019-05-03T12:01:07Z'),
$lte: ISODate('2019-05-07T12:01:07Z')
}
}
},
{ $addFields: {
date_string: { $dateToString: { format: "%Y-%m-%d", date: "$date" } }
}
},
{ $sort: { date: -1 } },
{ $group: {
_id: "$date_string",
my_doc: { $first: "$$ROOT" }
}
},
{ $replaceRoot: { newRoot: "$my_doc" } },
{ $project: { date_string: 0 } },
{ $sort: { date: 1 } }
])
答案 1 :(得分:1)
我找到了解决方案,我添加了分钟变量并使用它进行了匹配。还将组数据更改为$ last而不是$ first。
db.getCollection('weightedaverages').aggregate([
{
$match: {
date: { $gte: ISODate('2019-05-26T15:00:00.000Z'), $lte: ISODate('2019-10-26T15:00:00.000Z') }
}
},
{
$project: {
_id: 1,
value: 1,
docDate: '$date',
day: {
'$dayOfMonth': '$date'
},
month: {
'$month': '$date'
},
year: {
'$year': '$date'
},
minutes: {
$add: [
{
$multiply: [
{
'$hour': '$date'
},
60
]
},
{
'$minute': '$date'
}
]
}
}
},
{ $match: { 'minutes' : { $lte : ISODate('2019-10-26T13:20:00.000Z').getHours() * 60 + ISODate('2019-10-26T13:20:00.000Z').getMinutes()}}},
{
$project: {
_id: 1,
value: 1,
docDate: 1,
date: {
'$concat': [
{
$substr: ['$year', 0, 4]
},
'-',
{
$substr: ['$month', 0, 2]
},
'-',
{
$substr: ['$day', 0, 2]
}
]
}
}
},
{
$group: {
_id: '$date',
objId: {
$last: '$_id'
},
value: {
$last: '$value'
},
date: {
$last: '$docDate'
}
}
},
{
$project: {
_id: '$objId',
value: 1,
date: 1
}
},
{
'$sort': {
date: 1
}
}
]
)
输出:
{
"date" : ISODate("2019-08-20T15:00:13.633Z"),
"value" : 10
},
{
"date" : ISODate("2019-08-19T15:00:19.850Z"),
"value" : 5
},
...
{
"date" : ISODate("2019-06-20T14:59:48.000Z"),
"value" : 7
}