我按月列出员工存在数据（存在=＆＃39; T＆＃39;，不存在=＆＃39; F＆＃39;），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
---------------------------------------------------------------
我想获得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（自1月起他已经存在）和结束日期为2015年7月31日（因为员工在8月份被终止）
---------------------------------------------------------------------------------
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。有人可以帮助我实现这个目标。
答案 0 :(得分：1)
你可以尝试这样的事情。请注意，我强烈建议不要这样做，并使用PL / SQL或其他编程语言进行逻辑。 我还没有测试过（还）。我将根据我的测试（或删除我的答案）逻辑进行更新。作品。 SQLfiddle补充道。
（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。如果可以避免的话，请不要使用它。
答案 1 :(得分：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
欣赏。
答案 2 :(得分：0)
您好，只是尝试了解决此问题的非常简单的方法。希望它 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-----------------------------------------