CODEWITHSUNDEEP
mongodbmeteormongodb-queryaggregation-framework
Stroumphette-ES
Stroumphette-ES

Reputation: 109

Select all where the months of "date" is December in Mongodb?

Do you know if I can do a findAll where the month of Date is December?

I try this request but it's not good:

db.myCollection.aggregate({}, { "Date": { $month: 12 } });

it's similar to a SELECT * FROM table WHERE Months(date)=december?

Upvotes: 2

Views: 2541

Answers (3)

Mazout
Mazout

Reputation: 104

db.collection('mycollection').find({"Date": {$month: 12}})

https://docs.mongodb.com/manual/reference/method/db.collection.find/

Upvotes: 0

Thomas Ryder
Thomas Ryder

Reputation: 23

This should work for finding records in December for a given year, if that is enough to suit your purposes.

db.myCollection.find({
    "Date":{
        $gte:new Date("2016-12-01T00:00:00Z"),
        $lt:new Date("2017-01-01T00:00:00Z")
}})

Upvotes: -1

chridam
chridam

Reputation: 103375

Consider running an aggregation pipeline that uses the $redact operator as it allows you to incorporate with a single pipeline, a functionality with $project to create a field that represents the month of a date field and $match to filter the documents which match the given condition of the month being December.

In the above, $redact uses $cond tenary operator as means to provide the conditional expression that will create the system variable which does the redaction. The logical expression in $cond will check for an equality of a date operator field with a given value, if that matches then $redact will return the documents using the $$KEEP system variable and discards otherwise using $$PRUNE.

Running the following pipeline should give you the desired result:

db.myCollection.aggregate([
    {
        "$redact": {
            "$cond": [
                { "$eq": [{ "$month": "$Date" }, 12] },
                "$$KEEP",
                "$$PRUNE"
            ]
        }
    }
])

This is similar to a $project +$match combo but you'd need to then select all the rest of the fields that go into the pipeline:

db.myCollection.aggregate([
    {
        "$project": {
            "month": { "$month": "$Date" },
            "field1": 1,
            "field2": 1,
            .....
        }
    },
    { "$match": { "month": 12 } }
])

With another alternative, albeit slow query, using the find() method and $where as:

db.myCollection.find({ "$where": "this.Date.getMonth() === 11" })

Upvotes: 3

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