可以很方便的查出表中的所有字段，开发时可用上，免得一个一个字段的书写。
Select  max(SYS_CONNECT_BY_PATH(COLUMN_NAME, ', '))
From (select A.COLUMN_NAME,A.TABLE_NAME, ROWNUM AS ROWNO
from USER_TAB_COLUMNS A
where TABLE_NAME = '表名称'
ORDER BY A.COLUMN_ID)
start with ROWNO = 1
connect by ROWNO = rownum;