To easily manage the permissions in your databases, SQL Server provides several *roles that are security principals that group other principals. They are like groups in the Microsoft Windows operating system. Database-level roles are database-wide in their permissions scope.
To add and remove users to a database role, use the
ADD MEMBER and
DROP MEMBER options of the ALTER ROLE statement. Analytics Platform System (PDW) and Azure Synapse doesn't support this use of
ALTER ROLE. Use the older sp_addrolemember and sp_droprolemember procedures instead.
There are two types of database-level roles: fixed-database roles that are predefined in the database and user-defined database roles that you can create.
Fixed-database roles are defined at the database level and exist in each database. Members of the db_owner database role can manage fixed-database role membership. There are also some special-purpose database roles in the msdb database.
You can add any database account and other SQL Server roles into database-level roles.
Do not add user-defined database roles as members of fixed roles. This could enable unintended privilege escalation.
For a list of all the permissions, see the Database Engine Permissions poster. Server-level permissions cannot be granted to database roles. Logins and other server-level principals (such as server roles) cannot be added to database roles. For server-level security in SQL Server, use server roles instead. Server-level permissions cannot be granted through roles in SQL Database and Azure Synapse.
The following table shows the fixed-database roles and their capabilities. These roles exist in all databases. Except for the public database role, the permissions assigned to the fixed-database roles cannot be changed.
|Fixed-Database role name||Description|
|db_owner||Members of the db_owner fixed database role can perform all configuration and maintenance activities on the database, and can also
|db_securityadmin||Members of the db_securityadmin fixed database role can modify role membership for custom roles only and manage permissions. Members of this role can potentially elevate their privileges and their actions should be monitored.|
|db_accessadmin||Members of the db_accessadmin fixed database role can add or remove access to the database for Windows logins, Windows groups, and SQL Server logins.|
|db_backupoperator||Members of the db_backupoperator fixed database role can back up the database.|
|db_ddladmin||Members of the db_ddladmin fixed database role can run any Data Definition Language (DDL) command in a database. Members of this role can potentially elevate their privileges by manipulating code that may get executed under high privileges and their actions should be monitored.|
|db_datawriter||Members of the db_datawriter fixed database role can add, delete, or change data in all user tables. In most use cases this role will be combined with db_datareader membership to allow reading the data that is to be modified.|
|db_datareader||Members of the db_datareader fixed database role can read all data from all user tables and views. User objects can exist in any schema except sys and INFORMATION_SCHEMA.|
|db_denydatawriter||Members of the db_denydatawriter fixed database role cannot add, modify, or delete any data in the user tables within a database.|
|db_denydatareader||Members of the db_denydatareader fixed database role cannot read any data from the user tables and views within a database.|
The permissions assigned to the fixed-database roles cannot be changed. The following figure shows the permissions assigned to the fixed-database roles:
Special roles for SQL Database and Azure Synapse
These database roles exist only in the virtual master database. Their permissions are restricted to actions performed in master. Only database users in master can be added to these roles. Logins cannot be added to these roles, but users can be created based on logins and then those users can be added to the roles. Contained database users in master can also be added to these roles. However, contained database users added to the dbmanager role in master cannot be used to create new databases.
|dbmanager||Can create and delete databases. A member of the dbmanager role that creates a database, becomes the owner of that database, which allows that user to connect to that database as the dbo user. The dbo user has all database permissions in the database. Members of the dbmanager role don't necessarily have permission to access databases that they don't own.|
|db_exporter||Applies only to Azure Synapse Analytics dedicated SQL pools (formerly SQL DW).
Members of the db_exporter fixed database role can perform all data export activities. Permissions granted via this role are CREATE TABLE, ALTER ANY SCHEMA, ALTER ANY EXTERNAL DATA SOURCE, ALTER ANY EXTERNAL FILE FORMAT.
|loginmanager||Can create and delete logins in the virtual master database.|
The server-level principal and the Azure Active Directory Administrator (if configured) have all permissions in the SQL Database and Azure Synapse without needing to be members of any roles. For more information, see SQL Database Authentication and Authorization: Granting Access.
Some database roles aren't applicable to Azure SQL or Azure Synapse:
- db_backupoperator is not applicable in Azure SQL database (not managed instance) and Azure Synapse serverless pool because backup and restore T-SQL commands are not available.
- db_datawriter and db_denydatawriter are not applicable to Azure Synapse serverless because it just reads external data.
The msdb database contains the special-purpose roles that are shown in the following table.
|msdb role name||Description|
|Members of these database roles can administer and use SSIS. Instances of SQL Server that are upgraded from an earlier version might contain an older version of the role that was named using Data Transformation Services (DTS) instead of SSIS. For more information, see Integration Services Roles (SSIS Service).|
|Members of these database roles can administer and use the data collector. For more information, see Data Collection.|
|PolicyAdministratorRole||Members of the db_ PolicyAdministratorRole database role can perform all configuration and maintenance activities on Policy-Based Management policies and conditions. For more information, see Administer Servers by Using Policy-Based Management.|
|Members of these database roles can administer and use registered server groups.|
|dbm_monitor||Created in the msdb database when the first database is registered in Database Mirroring Monitor. The dbm_monitor role has no members until a system administrator assigns users to the role.|
Members of the db_ssisadmin role and the dc_admin role may be able to elevate their privileges to sysadmin. This elevation of privilege can occur because these roles can modify Integration Services packages and Integration Services packages can be executed by SQL Server using the sysadmin security context of SQL Server Agent. To guard against this elevation of privilege when running maintenance plans, data collection sets, and other Integration Services packages, configure SQL Server Agent jobs that run packages to use a proxy account with limited privileges or only add sysadmin members to the db_ssisadmin and dc_admin roles.
Working with database-level roles
The following table explains the commands, views, and functions for working with database-level roles.
|sp_helpdbfixedrole (Transact-SQL)||Metadata||Returns a list of the fixed database roles.|
|sp_dbfixedrolepermission (Transact-SQL)||Metadata||Displays the permissions of a fixed database role.|
|sp_helprole (Transact-SQL)||Metadata||Returns information about the roles in the current database.|
|sp_helprolemember (Transact-SQL)||Metadata||Returns information about the members of a role in the current database.|
|sys.database_role_members (Transact-SQL)||Metadata||Returns one row for each member of each database role.|
|IS_MEMBER (Transact-SQL)||Metadata||Indicates whether the current user is a member of the specified Microsoft Windows group or Microsoft SQL Server database role.|
|CREATE ROLE (Transact-SQL)||Command||Creates a new database role in the current database.|
|ALTER ROLE (Transact-SQL)||Command||Changes the name or membership of a database role.|
|DROP ROLE (Transact-SQL)||Command||Removes a role from the database.|
|sp_addrole (Transact-SQL)||Command||Creates a new database role in the current database.|
|sp_droprole (Transact-SQL)||Command||Removes a database role from the current database.|
|sp_addrolemember (Transact-SQL)||Command||Adds a database user, database role, Windows login, or Windows group to a database role in the current database. All platforms except Analytics Platform System (PDW) and Azure Synapse should use
|sp_droprolemember (Transact-SQL)||Command||Removes a security account from a SQL Server role in the current database. All platforms except Analytics Platform System (PDW) and Azure Synapse should use
|GRANT||Permissions||Adds permission to a role.|
|DENY||Permissions||Denies a permission to a role.|
|REVOKE||Permissions||Removes previously granted or denied permissions.|
Public database role
Every database user belongs to the public database role. When a user hasn't been granted or denied specific permissions on a securable object, the user inherits the permissions granted to public on that object. Database users cannot be removed from the public role.
The examples in this section show how to work with database-level roles.
A. Adding a User to a database-level role
The following example adds the User 'Ben' to the fixed database-level role
ALTER ROLE db_datareader ADD MEMBER Ben; GO
B. Listing all database-principals that are members of a database-level role
The following statement returns all members of any database role.
SELECT roles.principal_id AS RolePrincipalID , roles.name AS RolePrincipalName , database_role_members.member_principal_id AS MemberPrincipalID , members.name AS MemberPrincipalName FROM sys.database_role_members AS database_role_members JOIN sys.database_principals AS roles ON database_role_members.role_principal_id = roles.principal_id JOIN sys.database_principals AS members ON database_role_members.member_principal_id = members.principal_id; GO