PL/SQL-根据列值查询开始和结束日期

Question

我有一个按月列出的员工存在数据列表（Exist='T'，Not Exist ='F'），数据如下所示。

DepNo   Empno   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
---------------------------------------------------------------
1234    100     T   T   T   T   T   T   T   F   F   F   F   F
1234    101     T   T   T   T   F   F   F   F   F   F   F   F
1234    102     F   F   F   F   T   T   T   T   T   T   T   T
1234    103     F   F   F   F   T   T   T   F   F   F   F   F
---------------------------------------------------------------

我想获取每位员工的开始和结束日期。例如，员工 100 的开始日期是 2015 年 1 月 1 日（因为他存在于 1 月），结束日期是 2015 年 7 月 31 日（因为员工在 8 月被终止

---------------------------------------------------------------------------------
DepNo   Empno   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec StartDt EndDt
----------------------------------------------------------------------------------
1234    100     T   T   T   T   T   T   T   F   F   F   F   F   1-Jan-15 31-Jul-15
1234    101     T   T   T   T   F   F   F   F   F   F   F   F   1-Jan-15 30-Apr-15
1234    102     F   F   F   F   T   T   T   T   T   T   T   T   1-May-15 31-Dec-15
1234    103     F   F   F   F   T   T   T   F   F   F   F   F   1-May-15 31-Jul-15
----------------------------------------------------------------------------------

我正在使用 Oracle 11g。有人可以帮我实现这一目标吗？

Answer 1

准备环境。

create table tab1(depno number,empno number, jan char(1),feb char(1),mar char(1),apr char(1),may char(1),jun char(1),jul char(1),aug char(1),sep char(1),oct char(1),nov char(1),dec char(1));
insert into tab1 values(1234,100,'T','T','T','T','T','T','T','F','F','F','F','F');
insert into tab1 values(1234, 101,'T','T','T','T','F','F','F','F','F','F','F','F');
insert into tab1 values(1234, 102,'F','F','F','F','T','T','T','T','T','T','T','T');
insert into tab1 values(1234,103,'F','F','F','F','T','T','T','F','F','F','F','F');

运行此查询

select tab1.*,t3.startd,t3.endd from tab1, (select depno,empno,min(to_date('2015.'||monthh1||'.01','yyyy.mm.dd')) as startd, max(add_months(to_date('2015.'||monthh1||'.01','yyyy.mm.dd'),1)-1) as endd from (select t1.depno,t1.empno,decode(monthh,'JAN',1,'FEB',2,'MAR',3,'APR',4,'MAY',5,'JUN',6,'JUL',7,'AUG',8,'SEP',9,'OCT',10,'NOV',11,'DEC',12,-1) monthh1,statee from (select * from tab1 unpivot (statee for monthh in(jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec))) t1) t2 where statee='T' group by depno,empno)t3 where tab1.depno=t3.depno and tab1.empno=t3.empno order by tab1.depno,tab1.empno

享受吧。

Answer 2

你可以试试这样的。请注意，我强烈建议不要这样做并使用 PL/SQL 或其他一些编程语言作为逻辑。 我还没有测试过这个（还）。我将根据我的测试（或删除我的答案）逻辑进行更新。作品。已添加 SQLfiddle。

(http://sqlfiddle.com/#!4/30fc1/12):

 select e.empno, 
       1 start_day, 
       (case when EXTRACT(month FROM e.StartDt) > t.start_month 
             then EXTRACT(month FROM e.StartDt) 
             else t.start_month end) start_month, 
       EXTRACT(year FROM e.StartDt) start_year,
       to_date(1  || '-' ||
       (case when EXTRACT(month FROM e.StartDt) > t.start_month 
             then EXTRACT(month FROM e.StartDt) 
             else t.start_month end) || '-' ||
       EXTRACT(year FROM e.StartDt), 'dd-mm-yyyy') start_date
from employee e, 
     (select empno, 
             decode(Jan, 'T', 1, 
             decode(Feb, 'T', 2, 
             decode(Mar, 'T', 3, 
             decode(Apr, 'T', 4, 
             decode(May, 'T', 5, 
             decode(Jun, 'T', 6, 
             decode(Jul, 'T', 7, 
             decode(Aug, 'T', 8, 
             decode(Sep, 'T', 9, 
             decode(Oct, 'T', 10, 
             decode(Nov, 'T', 11, 
             decode(Decm, 'T', 12, 0)))))))))))) start_month
       from employee) t
where e.empno = t.empno

您可以根据这个想法获得结束日期。同样，如果可以避免，请不要使用它。

Answer 3

您好刚刚尝试了解决此问题的非常简单的方法。希望它 有帮助。如有任何问题，请告诉我。

    ALTER SESSION SET NLS_DATE_FORMAT = 'DD/MM/YYYY';

    SELECT a.EMPNO,
      to_date('01/'
      ||COALESCE(DECODE(a.dec,'F',NULL,'12/'),DECODE(a.nov,'F',NULL,'11/'),DECODE(a.oct,'F',NULL,'10/'),DECODE(a.sep,'F',NULL,'09/'),DECODE(a.aug,'F',NULL,'08/'),DECODE(a.jul,'F',NULL,'07/'),DECODE(a.june,'F',NULL,'06/'),DECODE(a.MAY,'F',NULL,'05/'),DECODE(a.april,'F',NULL,'04/'),DECODE(a.march,'F',NULL,'03/'),DECODE(a.feb,'F',NULL,'02/'),DECODE(a.jan,'F',NULL,'01/'))
      ||extract(YEAR FROM sysdate),'DD/MM/yyyy') STR,
      TO_DATE('01/'
      ||COALESCE(DECODE(a.dec,'F',NULL,'12/'),DECODE(a.nov,'F',NULL,'11/'),DECODE(a.oct,'F',NULL,'10/'),DECODE(a.sep,'F',NULL,'09/'),DECODE(a.aug,'F',NULL,'08/'),DECODE(a.jul,'F',NULL,'07/'),DECODE(a.june,'F',NULL,'06/'),DECODE(a.MAY,'F',NULL,'05/'),DECODE(a.april,'F',NULL,'04/'),DECODE(a.march,'F',NULL,'03/'),DECODE(a.feb,'F',NULL,'02/'),DECODE(a.jan,'F',NULL,'01/'))
      ||extract(YEAR FROM sysdate),'DD/MM/yyyy') ED_DT
    FROM
      (SELECT 10 AS DPT,
        1 EMPNO,
        'T' AS jan,
        'T' AS feb,
        'T' AS march,
        'T' AS april,
        'T' AS may,
        'T' AS JUNE,
        'T' AS jul,
        'F' AS aug,
        'F' AS sep,
        'F' AS oct,
        'F' AS nov,
        'F' AS DEC
      FROM dual
      UNION ALL
      SELECT 10 AS DPT,
        2 EMPNO,
        'T' AS jan,
        'T' AS feb,
        'T' AS march,
        'T' AS april,
        'F' AS may,
        'F' AS JUNE,
        'F' AS jul,
        'F' AS aug,
        'F' AS sep,
        'F' AS oct,
        'F' AS nov,
        'F' AS DEC
      FROM dual
      UNION ALL
      SELECT 10 AS DPT,
        3 EMPNO,
        'F' AS jan,
        'F' AS feb,
        'F' AS march,
        'F' AS april,
        'T' AS may,
        'T' AS JUNE,
        'T' AS jul,
        'T' AS aug,
        'T' AS sep,
        'T' AS oct,
        'T' AS nov,
        'T' AS DEC
      FROM dual
      UNION ALL
      SELECT 10 AS DPT,
        4 EMPNO,
        'F' AS jan,
        'F' AS feb,
        'F' AS march,
        'F' AS april,
        'T' AS may,
        'T' AS JUNE,
        'T' AS jul,
        'F' AS aug,
        'F' AS sep,
        'F' AS oct,
        'F' AS nov,
        'F' AS DEC
      FROM dual
      )A;

-------------------------------OUTPUT-----------------------------------------

EMPNO     STR              ED_DT
1   01/07/2015  01/07/2015
2   01/04/2015  01/04/2015
3   01/12/2015  01/12/2015
4   01/07/2015  01/07/2015

-------------------------------OUTPUT-----------------------------------------