SQL Server Database and Server Roles for Security and Permissions (2024)

By: Nivritti Suste |Updated: 2024-08-13 |Comments | Related: > Security

Problem

SQL Server is one of the most used relational database management systems inmany organizations. It is mainly used to store, manage, and retrieve data with ease.Apart from this, SQL Server is popular for data security, including encryption,data masking, and role-based access control.

Today, we will discuss role-based access control (RBAC) in SQL Server. UsingRBAC, you can assign specific permissions to users according to their roles withinthe server. There are different types of roles in SQL Server, which can be confusing.Here, we will discuss the distinctions between SQL Server and Database roles,helping us to manage security more effectively.

Solution

Let's first understand the roles. There are two types of roles in SQL Server:1) SQL Server Roles and 2) Database Roles.

What are SQL Server Roles?

SQL Server roles are predefined sets of permissions used to control access toserver resources. They are created at the server level and typically assigned tologins or other server roles, which helps administrators manage permissions andsecurity for the entire SQL Server instance. SQL Server roles are like Windows groups,allowing for easy management and assignment of permissions to multiple users.

Types of SQL Server Roles

There are three types of SQL Server roles: fixed server, user-defined server,and application.

Fixed SQL Server Roles - Fixed server roles are predefined sets of server-level permissions thatcannot be modified or deleted. These roles are created during the installationof SQL Server. This includes one of the important 'sysadmin' roles,which has "God-level control" over the entire SQL Server instance, andother specialized roles like bulkadmin, dbcreator, diskadmin.

User-Defined SQL Server Roles - There are multiple instances when you need custom sets of permissions basedon your business needs. Here, user-defined server roles come into the picture; theseare not predefined roles. User-defined server roles will allow you to create customsets of permissions based on your specific needs. These roles granted to loginsor only other user-defined server roles provide more control over access to server-wideresources.

SQL Server Application Roles - The above-mentioned roles are mostly assigned to individual users. Thisthird type of role is like user-defined server roles called Application Roles. Theseroles are created for applications only and used by applications instead of anyindividual users. These special roles let applications borrow permissions for ashort time to complete the task, keeping regular users and app users separate andsafe.

Key Features of SQL Server Roles

• Scope: Server-wide
• Creation: Created at the server level
• Assignment: Assigned to logins or other roles
• Permissions: Control access to server resources (databases,logins, etc.)

Example:SQL Code to Create a SQL Server Role

1. Create a SQL Server Role. Replace [role_name]with the desired name for your new server role.

CREATE ROLE [role_name];

2. Assign the User to the Role. Replace [role_name]with the name you chose in Step 1 and [user_name] with the username you wantto assign the role to.

ALTER ROLE [role_name] ADD MEMBER [user_name];

Note:

• You need to have sufficient permissions (e.g., sysadmin server role) to createserver roles and manage user memberships.
• This code snippet only creates the role and assigns the user. You'llneed to grant specific permissions to the role itself to control user access withinthe server.

Example: Granting Permissions to the Role

You can use the GRANT statement.

GRANT CONNECT TO SERVER TO [role_name];

This grants the "Connect to Server" permission to the newly createdrole. You can explore other permission options based on your needs.

How to Check Server Roles Using SSMS

1. Open SSMS and connect to your SQL Server.
2. In the Object Explorer, navigate to Security >Server Roles.
3. Expand the Server Roles. You will see all the predefinedand user-defined roles listed.

Alternatively, you can use SQL Query:

SELECT NAME FROM sys. server_principalsWHERE type_desc = 'SERVER_ROLE';

What are SQL Server Database Roles?

The Database Roles, as the name suggests, are specific to control databases anddatabase objects. Unlike server roles, these roles are created and managed at thedatabase level and can be assigned to database users and other roles within thesame database they are created. These roles are a more controlled approach to managingpermissions in a SQL Server instance as different users may have different levelsof permissions.

Types of SQL Server Database Roles

There are also three types of database roles: fixed database, user-defined database,and application.

Fixed SQL Server Database Roles - Fixed database roles are like fixed server roles in that they cannot bemodified or deleted. However, they are limited to the specific database in whichthey were created. The default fixed database role is 'db_owner',which has full control over the entire database and other roles like db_accessadmin,db_backupoperator,and db_datareader.

User-Defined SQL Server Database Roles - User-defineddatabase roles allow for the creation of custom sets of permissions within a specificdatabase. These roles can be assigned to users or other user-defined database roles,allowing for more granular control over access to objects within that database.

SQL Server Application Roles - Like SQL Server roles, application roles at the database level are intendedfor use by applications rather than normal users. They enable applications to temporarilyassume permissions and perform actions on behalf of the role, providing an addedlayer of security.

Key Features

• Scope: Database-specific
• Creation: Created at the database level
• Assignment: Assigned to database users or other roles
• Permissions: Control access to specific database objects(tables, views, etc.)

Example:SQL Code to Create a Database Role

1. Create a Database Role

CREATE ROLE [role_name] AUTHORIZATION [user_name]

• Replace the following:
  • [role_name]: The desired name for your new database role.
  • [user_name]: The username who will own (own as in "be authorizedby") the role. This user doesn't necessarily need to be the oneassigned to the role.

This statement combines the CREATE ROLE and AUTHORIZATIONclauses in a single line. The AUTHORIZATION clause specifies the user who will "own"the database role. This doesn't necessarily restrict who can be assigned tothe role, but it determines who can manage the role's permissions later (e.g.,adding/removing members and granting/revoking permissions to the role).

2. Assigning a User to the Database Role

ALTER ROLE [role_name] ADD MEMBER [user_name];

• Replace the following:
  • [role_name]: The name of the database role you created.
  • [user_name]: The username you want to assign to the database role.

This will grant the user the permissions associatedwith the database role.

Note:

• You need to have the db_owner role or equivalent permissions on the databaseto create database roles and manage user memberships.
• Remember to grant specific permissions to the database role itself to controluser access within the database. You can use the GRANT statement for this purpose.

How to Check Database Roles Using SSMS

1. In SSMS, navigate to the specific database you want tocheck.
2. Right-click on "Security" and select "Roles".
3. This will show you a list of all the roles defined within that database.

Another wayto check database roles with a system view:

1. Open a new query window in SSMS.
2. Use the below query to check all 'Database_Role.'

SELECT NAME FROM sys.database_principalsWHERE type_desc = 'DATABASE_ROLE';

Roles Key Differences Brief

When to Use Which Role

• SQL Server Roles: To manage overall user accessto the SQL Server instance and its resources.
• Database Roles: To grant granular permissions withinspecific databases based on user needs.

Best Practices for Using SQL Server andDatabase Roles

Follow these tips to keep things safe and organized when setting up who can accesswhat in SQL Server:

• Limit Sharing: Only give roles what they need. Don'tgive extra access.
• Keep Checking: As things change, update roles so accessstays right.
• Give Just Enough: Roles and users should only have whatthey need to do their job.
• Make Your Own Roles: Don't use predefined roles. Createones that fit your needs.
• Roles for Jobs: Use roles for different jobs to keep thingsorganized.
• Write it Down: Keep track of all the roles, so you don'tget confused.
• Double Check: Look at the roles regularly to make sure everythingis safe.

Conclusion

Understanding the difference between SQL Server roles and database roles is importantto keep your SQL Server secure. SQL Server roles provide server-wide control, whiledatabase roles offer more controlled permissions within specific databases. By leveragingthese roles appropriately, database administrators and SQL developers can enhancesecurity, streamline permission management, and ensure users have the necessaryaccess without compromising security.

Next Steps

• Check out these MSSQLTips.comSecurity tips.

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Article Last Updated: 2024-08-13