在mongodb中，show users 和db.system.users.find() 都能查看账户的相关信息，但是这两个命令有什么区别么？

　　db.system.users.find() 是查看全局的所有账户

> use adminswitched to db admin> db.system.users.find(){ "_id" : "admin.admin", "user" : "admin", "db" : "admin", "credentials" : { "SCRAM-SHA-1" : { "iterationCount" : 10000, "salt" : "+g1F+At5S9rC9fqIyHxDzA==", "storedKey" : "FOt1FE9+LqbcTQamwceQwULGJbY=", "serverKey" : "qZQWdSuYpH3E7k5GP30COrPqqZ8=" } }, "roles" : [ { "role" : "userAdminAnyDatabase", "db" : "admin" } ] }{ "_id" : "demo.myuser", "user" : "myuser", "db" : "demo", "credentials" : { "SCRAM-SHA-1" : { "iterationCount" : 10000, "salt" : "rGTxEaSNry22EOFnjaAjAw==", "storedKey" : "/kWOpCEWm+iI/ESecqy2JkIXJFo=", "serverKey" : "A66NeaeGo8XhwgrKKeD0ASEN0Uc=" } }, "roles" : [ { "role" : "dbOwner", "db" : "mydb" }, { "role" : "readWrite", "db" : "mydb" } ] }

　　show users 是查看当前库下的账户

> use admin switched to db admin > show users{        "_id" : "admin.admin",        "user" : "admin",        "db" : "admin",        "roles" : [                {                        "role" : "userAdminAnyDatabase",                        "db" : "admin"                }        ]}