title: SQL SERVER: Lack of permissions for user to create copy of database with all privileges
body: <h3>First of all, here it is what I've got:</h3>
  <ul>
  <li>two users: user and sa</li>
  <li>sa is database admin</li>
  <li>one main database with readonly permissions (db_datareader role) and executing some selected stored procedures (including database copying procedure) for user</li>
  <li>user has global dbcreator role</li>
  <li>SQL Server is located on a Windows Server machine with granted permissions for reading/writing files</li>
  <li>database copying stored procedure which when sa or user executes the procedure, it copies the db with all its content and granted permissions for user in original db. Afterwards sa has to map user to copied db and add him db_owner role.</li>
  </ul>
  <h3>What I already tried:</h3>
  <ul>
  <li>to add execute as sa to procedure, but user can't IMPERSONATE sa (admin restriction)</li>
  <li>to add line to the procedure such as:
  <code>ALTER AUTHORIZATION ON DATABASE::copyDB TO user</code></li>
  </ul>
  <p>Just been wondering, if there is any possibility to grant temporary permission to user or just grant him ownership for the copied database in any other way.</p>