MongoDB type a attribute of document in collection

Question

I am currently working on a project that save regulary data to a MongoDB database. In this database I have a several element and each document contains date.

Problematic

The documents contains wrong type for date attribute. It's due of bad inserting, all documents have a date in string format. I can per one update each attribute with MongoDB Atlas graphical interface, but this solution is too long..

Question

I wanted to know if in MongoDB we have a solution to update the type of an attribute in all documents in a collection.

Answer 1

For your case, the simplest solution is using $toDate in an update with aggregation pipeline

db.collection.update({},
[
  {
    "$addFields": {
      "date": {
        "$toDate": "$date"
      }
    }
  }
])

Here is the Mongo playground for your reference.

If you need to cater with other date format, you can use $dateFromString.

db.collection.update({},
[
  {
    "$addFields": {
      "date": {
        "$dateFromString": {
          "dateString": "$date",
          "format": <your format here>
        }
      }
    }
  }
])

You can refer to this official documentation on $dateFromString regarding the format parser.