1. What is a Login?

• A login is what allows someone to have access to the Server
• Logins use the authentication modes, either Windows Credentials or SQL / Mixed Credentials
• General logins can be made for a group of people who are performing similar duties

2. Server Roles

Bulkadmin – Bulk operations like BI
Dbcreator – Create and drop databases
Diskadmin – Manage disk files on system
Processadmin – Control processes running in the database engine
Public – Default role
Securityadmin – Manage logins and users, do DCL
Serveradmin – Server wide configuration
Setupadmin – add linked servers
Sysadmin - Everything

3.Additional Options

User Mapping – lists all the possible databases and database roles of those databases that can be applied to the Login
Securables – Securities and permissions that can be granted to the login
Status – Allows for enabling or disabling of login and well as authentications and permissions

4.What is a User?

Database security access to specific databases
All logins must be mapped to a user to have access to a database
Partially contained DB’s can have users without logins

5. comparison

5.1 login

Used for server level permissions
Logins must be mapped to a user for access to a database
A single login can be linked to many users, making DCL statements easier
Instance Level Security Principal
Server Roles

5.2 user

Used for database level permissions
There can be users without a login if the database is partially contained
A single user can not be assigned to multiple logins
Database Level Security Principal
Database Roles

6. note

• like in county fair, login like 门票, user 像是每个项目的门票