MongoDB find by two fields code example

Example 1: mongo console find by id

db.collection.find({_id:ObjectId('5e208c18d598b806c869ca37')}).pretty()

Example 2: mongodb find documents where two fields are equal

db.myCollection.find( { $where: "this.a1.a != this.a2.a" } )

Example 3: mongodb find multiple fields

{ <field1>: <value>, <field2>: <value> ... }