1.在无密码模式下添加账号
db.createUser( { user: "user", pwd: "pwd", roles: [ { role: "readWrite", db: "test1" },{ role: "readWrite", db: "test2" } ] } )
2.角色权限说明
http://www.2cto.com/database/201507/420854.html
mongodb权限
原文：http://www.cnblogs.com/guochunyi/p/5253003.html
