将oracle数据库中所有表的注释导出导入

SELECT 'comment on column   '|| t.table_name||'.'||
       t.colUMN_NAME||'  is  '  || '  ''  ' ||
       t1.COMMENTS ||'  ''  '|| ';'
  FROM User_Tab_Cols t, User_Col_Comments t1
 WHERE t.table_name = t1.table_name
    AND t.column_name = t1.column_name(+)
    
    and t.table_name like '%T_XW_%';