Question: MongoDB creates a new database, and an error is reported when adding a user
Description: In the Alibaba Cloud server, after entering MongoDB, a new database is created. When creating a user for this database, an error is reported: Error: command createUser requires authentication
Solution: The reason isInstalled MongoDB with username and password authentication enabled, if you directly create a database user without logging in, an error will be reported, because there is no permission to create, you need to log in to the super user first, for example:
// 切换到默认数据库
use admin
// 登录，用户名和密码请根据自己创建时的设定修改
db.auth("admin","111111")
Switch to the database where the user needs to be created
// 切换数据库
use demo
// 创建用户名为demo,密码为111111的用户，并且该用户的权限是readWrite, 该用户作用于demo数据库
db.createUser({
user:'demo',pwd:'111111',roles:[ {
role:"readWrite", db:'demo'}]});