How I can find closest date by single request using pymongo? Date should be closest to Current Date-CodePudding

Dataset :

{"_id":{"$oid":"61e038a052124accf41cb5e4"},"event_date":{"$date":{"$numberLong":"1642204800000"}},
"name":"UFC Fight Night","event_url":"https://www.tapology.com/fightcenter/events/82805-ufc-fight-night","location":"Las Vegas, NV"}
{"_id":{"$oid":"61e038a252124accf41cb5e5"},"event_date":{"$date":{"$numberLong":"1642809600000"}},"name":"UFC 270","event_url":"https://www.tapology.com/fightcenter/events/82993-ufc-270","location":"Anaheim, CA"}
{"_id":{"$oid":"61e038a252124accf41cb5e6"},"event_date":{"$date":{"$numberLong":"1644019200000"}},"name":"UFC Fight Night","event_url":"https://www.tapology.com/fightcenter/events/83125-ufc-fight-night","location":"Las Vegas, NV"}

I'm using python, and that means I have no way to use $commands in my code for Mongo DB to find collection I need. Question is how can find object which should have datetime value closest to current date. As I understand I have to use python's datetime.now() to set current date and compare it ($currentDate doesn't work for Python). But but in order to compare values I have to deserialize the object and this looks very heavy. By default Mongo uses ISO datetime type.
Can you help me? At least direction to put me on a right way?

CodePudding user response：

Here is a solution with an aggregate

db.collection.aggregate([
  {
    "$addFields": {
      "dateDiff": {
        "$abs": {
          "$subtract": [
            "$event_date",
            {
              "$literal": new Date()
            }
          ]
        }
      }
    }
  },
  {
    "$sort": {
      "dateDiff": 1
    }
  }
])

I use $subtract to have a difference between event_date and today.
$abs is to have the absolute value. To have the closest in the future or in the past.
And then we just have to sort by dateDiff

In your code you have to replace new Date()

Try it here