Sql Server Create a User

Understanding SQL Server User Creation

Creating a user in SQL Server is a fundamental task for database administrators and developers. It is essential for managing access to the database and ensuring that only authorized individuals can perform certain actions. In SQL Server, users are associated with logins, which are the credentials used to connect to the server. A login grants access to the server, while a user account grants permissions to access databases and perform specific tasks within them.

Types of Users in SQL Server

Before diving into the process of creating a user, it’s important to understand the different types of users in SQL Server:

SQL Server Authenticated Users: These users are authenticated by SQL Server using a username and password.
Windows Authenticated Users: These users are authenticated through Windows and do not require a separate username and password for SQL Server.
Contained Database Users: These users are specific to a database and do not have a login at the server level. They are useful for scenarios where database portability is important.

Permissions and Roles

Users in SQL Server can be assigned specific permissions or roles that define what they can and cannot do. Roles are predefined sets of permissions that can be easily assigned to users. Common roles include:

db_owner: Has full control over the database.
db_securityadmin: Can modify role membership and manage permissions.
db_accessadmin: Can add or remove access to the database for Windows logins, Windows groups, and SQL Server logins.
db_datareader: Can read all data from all user tables.
db_datawriter: Can add, delete, or change data in all user tables.
db_ddladmin: Can run dynamic-link library (DDL) commands.

Step-by-Step Guide to Creating a SQL Server User

Before creating a user, you must first create a login unless you are creating a contained database user. Here’s how to create a SQL Server authenticated login:

CREATE LOGIN MyNewLogin WITH PASSWORD = 'StrongPassword!23';

For a Windows authenticated login, you would use:

CREATE LOGIN [DOMAINUsername] FROM WINDOWS;

Once you have a login, you can create a user in a specific database for that login:

USE MyDatabase;
CREATE USER MyNewUser FOR LOGIN MyNewLogin;

This creates a user named MyNewUser in MyDatabase that is associated with the MyNewLogin login.

Creating a Contained Database User

To create a contained database user with a password, you do not need to create a login:

USE MyDatabase;
CREATE USER MyContainedUser WITH PASSWORD = 'StrongPassword!23';

Assigning Roles and Permissions

After creating a user, you can assign roles or specific permissions to that user. To add a user to the db_datareader role, you would use:

USE MyDatabase;
ALTER ROLE db_datareader ADD MEMBER MyNewUser;

To grant specific permissions, such as SELECT on a table, you would use:

USE MyDatabase;
GRANT SELECT ON MyTable TO MyNewUser;

Best Practices for Managing SQL Server Users

Principle of Least Privilege

Always follow the principle of least privilege when assigning permissions. Users should only have the permissions necessary to perform their job functions and no more. This minimizes the risk of accidental or malicious data changes.

Regularly Reviewing User Access

Regularly review user access rights to ensure they are still appropriate. Remove or adjust permissions as necessary, especially when users change roles or leave the organization.

Using Strong Passwords

For SQL Server authenticated users, enforce strong password policies to prevent unauthorized access. SQL Server can enforce password complexity, expiration, and history.

Auditing and Monitoring

Implement auditing to track user access and activities. This can help identify potential security breaches or misuse of permissions.

Advanced User Management Techniques

Using Scripts for Bulk User Creation

For creating multiple users, scripts can be used to automate the process. This is especially useful in larger environments where manual creation would be time-consuming.

Dynamic SQL for User Management

Dynamic SQL can be used to build and execute SQL statements that can create or modify users based on variable inputs. This allows for more flexible user management.

Integrating with Active Directory Groups

For Windows authenticated users, use Active Directory groups to manage database access. This allows you to manage permissions at the group level rather than individually.

Frequently Asked Questions

Yes, you can create a contained database user without a server-level login. This is done using the CREATE USER statement with the WITH PASSWORD option within the context of a specific database.

How do I change a user’s password in SQL Server?

For SQL Server authenticated users, you can change the password using the ALTER LOGIN statement:

ALTER LOGIN MyNewLogin WITH PASSWORD = 'NewStrongPassword!45';

For contained database users, use the ALTER USER statement:

ALTER USER MyContainedUser WITH PASSWORD = 'NewStrongPassword!45';

How can I list all users in a SQL Server database?

You can list all users in a database by querying the sys.database_principals system view:

USE MyDatabase;
SELECT name, type_desc FROM sys.database_principals WHERE type IN ('U', 'S');

A login is a server-level principal that allows you to connect to the SQL Server instance. A user is a database-level principal that allows you to access and perform actions within a specific database.

How do I remove a user from SQL Server?

To remove a user from a database, use the DROP USER statement:

USE MyDatabase;
DROP USER MyNewUser;

Remember to also remove the associated login if it is no longer needed:

DROP LOGIN MyNewLogin;

References

Microsoft SQL Server Documentation: SQL Server Technical Documentation
SQL Server Security Best Practices: Security Best Practices with SQL Server
SQL Server Login and User Management: Create a Login and Create a Database User