SELECT LEVEL AS 周次
,TO_CHAR((TRUNC(sysdate,'YYYY')-7) + (7-TO_CHAR(TRUNC(sysdate,'YYYY'),'D')+1) + (LEVEL-1)*7-1,'yyyy-MM-dd') AS 当周第一天
,TO_CHAR((TRUNC(sysdate,'YYYY')-7) + (7-TO_CHAR(TRUNC(sysdate,'YYYY'),'D')+1) + (LEVEL-1)*7+5,'yyyy-MM-dd') AS 当周最后一天
FROM DUAL CONNECT BY LEVEL<=52