选择数据库 use admin
  添加用户:
        db.createUser(
                {
                    user: "admin",
                    pwd: "12345678",
                    roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
                 }
        )
  此命令创建的用户只有管理用户的权限,并没有操作数据库的权限。
  查看用户  show user 
  创建用户,用户都跟着库走,创建的用户都是
      use MutiQery
          db.createUser(
                {
                    user: "xxx",
                    pwd: "xxx123",
                    roles: [
                            { role: "readWrite", db: "MutiQery" }
                            ]
                            }
                    )
  查看mongoDB的所有用户
  use admin
  db.system.users.find()
  登陆验证
  use MutiQery
  db.auth("xxx","xxx123")
  show collections
10-10 01:48