declare
  v_res  varchar2(4000);
  v_sql  varchar2(4000);
  v_head varchar2(4000);
  v_last varchar2(4000);
  v_sqlall varchar2(4000);
begin
  for i in (select *
            from   user_tables a
            where  rownum < 10)
  loop
    v_head := 'select ' || '''' || 'public  static class   ' || i.table_name || '{ ' || '''' ||
              '  from dual ';
  
    v_last := 'select ' || '''' || '} ' || '''' || '  from dual ';
  
    v_sql := 'select * from   (select ' || '''' ||
             ' public static string  a.COLUMN_NAME  = ' || '''' || '||' || '''' || '"' || '''' || '||' ||
             'COLUMN_NAME' || '||' || '''' || '";' || '''' || ' ' ||
             '  from   user_tab_columns a' || '  where  a.TABLE_NAME = ' || '''' ||
             i.table_name || '''' || ' order  by a.COLUMN_ID)';
  v_sqlall := 'insert into test  select * from (' || v_head||'  union all  '|| v_sql ||'  union all '|| v_last||')';
  execute immediate v_sqlall;
  --dbms_output.put_line(v_res);
  end loop;
end;