How do you query for “is not null” in Mongo?

Question

I would like to execute the following query:

db.mycollection.find(HAS IMAGE URL)

What should be the correct syntax?

Answer 1

The query for “is not null” in Mongodb in pymongo you can use the following query:-

db.mycollection.find({"IMAGE URL":{"$ne":None}});

This is because pymongo represents mongo "null" as python "None".

Answer 2

Follow the following syntax:

db.collection1.find({ 'fieldname1' : { $exists: true, $ne: null } });

When $exists is true, $exists matches the documents that contain the particular field, including documents where the field value is null. If the value is false, the query returns only the documents that do not consist of the field. $ne picks the documents where the value of the field is not equal to the particularized value. This incorporates documents that do not contain the field.

Answer 3

The following Two methods can be used to resolved it  
Use the $ne operator with null, or combine $exists and $ne to make sure the field both exists and is non-null. 
Example 1: Using $ne 
 
db.collection.find({ fieldName: { $ne: null } }) 
 
This query returns documents where fieldName is explicitly not null. 
Example 2: Using $exists and $ne 
db.collection.find({ fieldName: { $exists: true, $ne: null } }) 
 
It returns only the documents where fieldName exists and is not null. These techniques are generally used for filtering out the MongoDB database documents.