How to use MongoDB’s insert and update updates

When we use MongoDB’s update, if we set the third parameter to true, a new document will be created if no document is found. The following is an example: >db.foo.find() { “_id” : ObjectId(“4e9165cf717ed94f8289ac0c”), “bar” : “baz”} >db.foo.update({“bar”:”baz”}, {“$inc”:{“count”:3}}) >db.foo.find() { “_id” : ObjectId(“4e9165cf717ed94f8289ac0c”), “bar” : “baz”, “count” : 3 } >db.foo.update({“bar”:”bazz”}, {“$inc”:{“count”:3}}) >db.foo.find() { “_id” : ObjectId(“4e9165cf717ed94f8289ac0c”), “bar” : “baz”, “count” : 3 } > db.foo.update({“bar”:”bazz”}, {“$inc”:{“count”:3}},true) > db.foo.find() { “_id” : ObjectId(“4e9165cf717ed94f8289ac0c”), “bar” : “baz”, “count” : 3 } { “_id” : ObjectId(“4e916661739f1da5452a4dfe”), “bar” : “bazz”, “count” : 3 } If the third parameter is not set to true in update, no action will be taken when the document to be updated cannot be found; if the third parameter is set to true, a new document will be created if no document is found.