确定当前记录和下一条记录之间相差的天数

CREATE OR REPLACE VIEW v AS
SELECT ‘1‘ AS id, DATE‘2015-1-1‘ AS hiredate FROM DUAL
UNION ALL
SELECT ‘2‘ AS id, DATE‘2015-5-1‘ AS hiredate FROM DUAL
UNION ALL
SELECT ‘3‘ AS id, DATE‘2015-3-1‘ AS hiredate FROM DUAL;

SELECT * FROM v;

SELECT id, hiredate, LEAD(hiredate) OVER(ORDER BY hiredate) next_hd FROM v;

SELECT id, hiredate, next_hd - hiredate AS diff
  FROM (SELECT id, hiredate, LEAD(hiredate) OVER(ORDER BY hiredate) next_hd
          FROM v);

SELECT id,
       hiredate,
       LEAD(hiredate) OVER(ORDER BY hiredate) lead_hd,
       hiredate,
       LAG(hiredate) OVER(ORDER BY hiredate) lag_hd
  FROM v;