Mongodb where is null

The above query is same as below. All the above answers are amazing and correct. Starting with MongoDB 3. So to summarize-. Remember, this will pull any document of emails which has any value including null , 0 , '' , false. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more.

MongoDB: How to query for records where field is null or not set? Ask Question. Asked 9 years, 6 months ago. Active 1 month ago. Viewed k times. I think this is the right way to get the sent count: db. Improve this question. Yves M. Andrew Andrew k gold badges silver badges bronze badges.

Add a comment. That query would look like this:. This is one advantage the existence and type check have over the other queries in that they are very explicity about what they return. The opposite query is quite helpful and comes up in many real world situations where you only want to operate on documents where that field exists with a value:. If we wanted to find documents where the department field did not existwe would filter for the Undefined type 6 :.

You provide this operator with a field and an array of values and it returns documents where the specified field is not in the list.

It also returns documents where that field does not exist. As you can see this is also a great query to find documents where a field does not exist or is not defined. There can be a lot of nuance to these queries but they are invaluable in the real world. To query for null or missing fields, see Query for Null or Missing Fields. The following scenario is not optimal because all of the collection's documents are examined:.

To improve performance, create a sparse index on the field as shown in the following scenario:. Create a sparse index on the auditDate field:. The following example counts the documents where the auditDate field has a value including null and uses the sparse index :.

The example returns 5. The document that is missing the auditDate value is not counted.