To easily manage the permissions in your databases, SQL Server provides several roles which 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.
There are two types of database-level roles in SQL Server: fixed database roles that are predefined in the database and flexible 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 fixed database roles in the msdb database.
You can add any database account and other SQL Server roles into database-level roles. Each member of a fixed database role can add other logins to that same role.
Do not add flexible database roles as members of fixed roles. This could enable unintended privilege escalation.
The following table shows the fixed database-level roles and their capabilities. These roles exist in all databases.
|Database-level 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 drop the database.|
|db_securityadmin||Members of the db_securityadmin fixed database role can modify role membership and manage permissions. Adding principals to this role could enable unintended privilege escalation.|
|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.|
|db_datawriter||Members of the db_datawriter fixed database role can add, delete, or change data in all user tables.|
|db_datareader||Members of the db_datareader fixed database role can read all data from all user tables.|
|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 in the user tables within a database.|
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
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 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.|
|sp_droprolemember (Transact-SQL)||Command||Removes a security account from a SQL Server role in the current database.|
public Database Role
Every database user belongs to the public database role. When a user has not been granted or denied specific permissions on a securable object, the user inherits the permissions granted to public on that object.