ORACLE查询出表中的字段列表

 SELECT max(SYS_CONNECT_BY_PATH(COLUMN_NAME, ','))
  FROM (SELECT A.COLUMN_NAME, ROWNUM AS ROWNO
          FROM USER_TAB_COLUMNS A
         WHERE TABLE_NAME = 'A_USER'
         order by a.COLUMN_ID)
start with ROWNO = 1
connect by ROWNO = rownum;