DROP SERVER ROLE (Transact-SQL)

role_name

Specifies the user-defined server role to be dropped from the server.

User-defined server roles that own securables cannot be dropped from the server. To drop a user-defined server role that owns securables, you must first transfer ownership of those securables or delete them.

User-defined server roles that have members cannot be dropped. To drop a user-defined server role that has members, you must first remove members of the role by using ALTER SERVER ROLE.

Fixed server roles cannot be removed.

You can view information about role membership by querying the sys.server_role_members catalog view.

Requires CONTROL permission on the server role or ALTER ANY SERVER ROLE permission.

A. To drop a server role

DROP SERVER ROLE purchasing;
GO

B. To view role membership

SELECT SRM.role_principal_id, SP.name AS Role_Name, 
SRM.member_principal_id, SP2.name  AS Member_Name
FROM sys.server_role_members AS SRM
JOIN sys.server_principals AS SP
    ON SRM.Role_principal_id = SP.principal_id
JOIN sys.server_principals AS SP2 
    ON SRM.member_principal_id = SP2.principal_id
ORDER BY  SP.name,  SP2.name

C. To view role membership

SELECT SP1.name AS RoleOwner, SP2.name AS Server_Role
FROM sys.server_principals AS SP1
JOIN sys.server_principals AS SP2
    ON SP1.principal_id = SP2.owning_principal_id 
ORDER BY SP1.name ;

Reference

Concepts