MongoDB: javascript execution failed : can't save a DBQuery object at src/mongo/shell/collection.js

Question

In MongoDb , when i try to modify existing document in collection , it generate the following exception : javascript execution failed : can't save a DBQuery object at src/mongo/shell/collection.js

In mongoDb shell i perform the following action :

 > var doc1 = db.users.find({name:"Harmeet"})
 > doc1.color = "Blue"
 > db.users.save(doc1)

when call to the save method the exception thow.

Answer 1

use var doc1 = db.users.findOne({name:"Harmeet"})

db.users.find returns a cursor.

Answer 2

虽然@Manuel Rony Gomes回答了这个问题，但是当你想要立即将从集合A中找到的多个文档插入到集合B中时，可以使用toArray（）让它工作：

db.coll_B.insert(db.coll_A.find({}).toArray())