Data type conversion in MongoDB

Question

I have a collection called Document in MongoDB. Documents in this collection have a field called CreationDate stored in ISO date type. My task is to count the number of docu

Answer 1

Another easier way you can convert ISODate to various date formats is to use the $dateToString aggregation operator.

db.collection.aggregate([
    { $group: {
        _id: { $dateToString: { format: "%Y-%m-%d %H:%M", date: "$CreationDate" } },
        count: { $sum: 1 }
    }},
    { $sort : { count: -1 }}
])