Why is MongoDB unique?

Question

MongoDB's Unique Constraint makes certain that the fields indexed in it, do not store duplicate values for the same field, i.e., making sure the uniqueness of fields. By default, MongoDB enforces this unique constraint on the “_id” field, while inserting new data.

Are MongoDB IDS unique?

MongoDB is a NoSQL database that operates with collections and documents. Each document created on MongoDB has a unique object ID property. So when creating a document without entering an ID, the document will be created with an auto-generated ID.

What is MongoDB distinct?

In MongoDB, the distinct() method finds the distinct values for a given field across a single collection and returns the results in an array. It takes three parameters first one is the field for which to return distinct values and the others are optional.

Does MongoDB allow duplicates?

To insert records in MongoDB and avoid duplicates, use “unique:true”. Let us first create a collection with documents.

How do I make an email unique in MongoDB?

Use unique keyword, or simply make _id value to be email.1I tried doing db. ... 2Creating a unique index and inserting a document without email you will achieve that. ... 3Also, you really should be controlling input in your application too.

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