Create a gist now

Instantly share code, notes, and snippets.

What would you like to do?
MongoDB Aggregation Framework way for "select count (distinct fieldName) from someTable" for large collections
//equivalent of "select count (distinct fieldName) from someTable"
db.someCollection.aggregate([{ $group: { _id: "$fieldName"} },{ $group: { _id: 1, count: { $sum: 1 } } } ])

Found this ^ when i wanted this:
returns a result with the distinct field names, and a count of the documents in the collection which have each distinct field value.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment