Change owner of folder in Blackboard database

ownership_procedure.sql

declare
    ow varchar(200);
    cb varchar(200);
    counter number;
    message varchar(200);
begin
    counter := 0;
    for uu in ( select pk1,  file_id , user_id, full_path, internal_principal_id
                from bblearn.users uu, bblearn_cms_doc.xyf_urls, bblearn_cms_doc.XYF_PRINCIPAL_LOOKUPS pp
                where FULL_PATH = '/users/'||uu.user_id and
                regexp_like(principal_id,'^BB:U:_[[:digit:]]*_1') and
                substr(substr(principal_id,1, length(principal_id)-2), 7) =to_char(uu.pk1) )
    loop
        select owner_principal_id, created_by into ow, cb from bblearn_cms_doc.XYF_FILES where FILE_ID = uu.file_id;
        if(ow != uu.internal_principal_id) then
            DBMS_OUTPUT.PUT_LINE('userid: ' ||uu.user_id || ' internal_principal_id: ' || uu.internal_principal_id || ' owner_principal_id: ' || ow);
            counter := counter +1;
            message := 'userid: '||uu.user_id;
            // you will need to build this update statement as follows,
            //please don't remove it if you don't know what you are doing.
            //this is the point of no return.
            //update bblearn_cms_doc.XYF_FILES set owner_principal_id = uu.internal_principal_id, created_by = uu.internal_principal_id where FILE_ID = uu.file_id;
        end if;
    end loop;
           DBMS_OUTPUT.PUT_LINE(counter);
    exception
        when NO_DATA_FOUND THEN DBMS_OUTPUT.PUT_LINE('the exception is with the user after this one ' || message);
end;
/