Mongodb request. How to find the one closest to the current date?

Question

I have such collections:

{
    "_id" : ObjectId("963fae9d93f4d930c98e269d"),
    "myDate":ISODate("2017-02-05T05:00:00.000Z"),
    "otherData":"blablabla"
},
{
    "_id" : ObjectId("963fae9d93f4d930c98e269d"),
    "myDate":ISODate("2017-02-05T14:00:00.000Z"),
    "otherData":"blablabla"
},
{
    "_id" : ObjectId("963fae9d93f4d930c98e269d"),
    "myDate":ISODate("2017-03-05T02:00:00.000Z"),
    "otherData":"blablabla"
},
{
    "_id" : ObjectId("963fae9d93f4d930c98e269d"),
    "myDate":ISODate("2017-03-05T19:00:00.000Z"),
    "otherData":"blablabla"
}

Given the current date (minutes and seconds), I want to find the record closest to the current date (in the "myDate" field).

thank

Answer 1

You can subtract the dates in your collection with the current date, accept the absolute value of the difference for consideration at a future date, and then use sorting and restriction to get the closest document:

db.a.aggregate([
{
    $project : {
        myDate : 1,
        otherData : 1,
        difference : {
            $abs : {
                $subtract : [new Date(), "$myDate"]
            }
        }
    }
},
{
    $sort : {difference : 1}
},
{
    $limit : 1
}
])

You can use optional $projectif you want to use the field differencein the output. Also, instead of the current date, you can use any other date and find the closest date to this date.

Answer 2

, , , , - a second(s), minute(s), hour(s) , day(s) or year(s). , ve current and current + nearest factor myDate

some_collection.find({
    myDate: {
        $gte: ISODate("2016-04-29T00:00:00.000Z"),
        $lt: ISODate("2017-05-01T00:00:00.000Z")
    }
})