DROP ROLE (Transact-SQL)
Removes a role from the database.
Roles that own securables cannot be dropped from the database. To drop a database role that owns securables, you must first transfer ownership of those securables or drop them from the database. Roles that have members cannot be dropped from the database. To drop a role that has members, you must first remove members of the role.
To remove members from a database role, use ALTER ROLE (Transact-SQL).
You cannot use DROP ROLE to drop a fixed database role.
Information about role membership can be viewed in the sys.database_role_members catalog view.
Beginning with SQL Server 2005, the behavior of schemas changed. As a result, code that assumes that schemas are equivalent to database users may no longer return correct results. Old catalog views, including sysobjects, should not be used in a database in which any of the following DDL statements have ever been used: CREATE SCHEMA, ALTER SCHEMA, DROP SCHEMA, CREATE USER, ALTER USER, DROP USER, CREATE ROLE, ALTER ROLE, DROP ROLE, CREATE APPROLE, ALTER APPROLE, DROP APPROLE, ALTER AUTHORIZATION. In such databases you must instead use the new catalog views. The new catalog views take into account the separation of principals and schemas that was introduced in SQL Server 2005. For more information about catalog views, see Catalog Views (Transact-SQL).
To remove a server role, use DROP SERVER ROLE (Transact-SQL).
The following example drops the database role purchasing from AdventureWorks2012.
USE AdventureWorks2012; DROP ROLE purchasing; GO