SELECT USER_TAB_COLS.TABLE_NAME   as 表名,

       UTC.COMMENTS               as 表中文名,

       USER_TAB_COLS.COLUMN_ID    as 列序号,

       USER_TAB_COLS.COLUMN_NAME  as 列名,

       USER_TAB_COLS.DATA_TYPE    as 数据类型,

       USER_TAB_COLS.DATA_LENGTH  as 长度,

       USER_TAB_COLS.NULLABLE     as 是否为空,

       user_col_comments.comments as 备注

  FROM USER_TAB_COLS

  left join user_tab_comments utc

    on USER_TAB_COLS.TABLE_NAME = utc.table_name

 inner join user_col_comments

    on user_col_comments.TABLE_NAME = USER_TAB_COLS.TABLE_NAME

   and user_col_comments.COLUMN_NAME = USER_TAB_COLS.COLUMN_NAME order by 表名,列序号