[{"_id":ObjectId("5e0b1b094dfee4f3a2f4f62a"),"name":"Jane Doe","email":"john_doe@gmail.com","status":"done","created_date":ISODate("2021-10-03T19:38:56.462Z"),"updated_date":ISODate("2021-10-03T19:38:56.462Z")},{"_id":ObjectId("5e0b1b094dcee4f3a2f4f62a"),"name":"Lorem Ipsum","email":"test@gmail.com","status":"done","created_date":ISODate("2021-10-03T19:38:56.462Z"),"updated_date":ISODate("2021-10-03T19:38:56.462Z"),"client_comment":"Lorem ipsum"},{"_id":ObjectId("5e0b1b094dfef4f3a2f4f62a"),"name":"John Doe","email":"jane.doe@gmail.com","status":"done","created_date":ISODate("2021-10-03T19:38:56.462Z"),"updated_date":ISODate("2021-10-03T19:38:56.462Z"),"client_comment":""}]

db.collection.find({$or:[{client_comment:{$exists:false}},{client_comment:{$ne:""}}]})