Sql query-urgent

Question

I would be thankful if anyone could please advise on the sql question as follows:
id1,dept1,JOHN,12-12-1991
id2,dept1,JOHN,12-12-1992
id3,dept1,JOHN,12-12-1993
id4,dept1,SMITH,11-10-1994
id5,dept1,SMITH,12-12-1995
id6,dept1,SMITH,12-12-1996
id7,dept1,CHRIS,07-07-1997
id8,dept1,CHRIS,12-12-1998
I need a query to get the the data when a particular employee was replaced
as follows:
name,date_replaced
JOHN,11-10-1993
SMITH,07-07-1997
CHRIS,null
Any suggestions are most welcome.

Answer 1

  1  select distinct name, last_value(NextHired) over (ORDER BY dept,name)
  2  from
  3  (with emp as
  4    (select 'id1' id,
  5            'dept1' dept,
  6            'JOHN' name,
  7            to_date('12-12-1991' ,'DD-MM-YYYY') hiredate from dual
  8     union
  9     select 'id2','dept1','JOHN',to_date('12-12-1992' ,'DD-MM-YYYY') from dual
10     union
11     select 'id3','dept1','JOHN',to_date('12-12-1993' ,'DD-MM-YYYY') from dual
12     union
13     select 'id4','dept1','SMITH',to_date('11-10-1994','DD-MM-YYYY') from dual
14     union
15     select 'id5','dept1','SMITH',to_date('12-12-1995','DD-MM-YYYY') from dual
16     union
17     select 'id6','dept1','SMITH',to_date('12-12-1996','DD-MM-YYYY') from dual
18     union
19     select 'id7','dept1','CHRIS',to_date('07-07-1997','DD-MM-YYYY') from dual
20     union
21     select 'id8','dept1','CHRIS',to_date('12-12-1998','DD-MM-YYYY') from dual)
22  select id,name, dept,lead (hiredate,1) OVER (ORDER BY hiredate) AS NextHired
23  from   emp
24  order by id, dept)
25* order by last_value(NextHired) over (ORDER BY dept,name)
SQL> /
JOHN  11/10/94
SMITH 07/07/97
CHRIS
SQL> Nicolas.
Message was edited by:
N. Gasparotto
Hmm, rajeevm, you wrote JOHN,11-10-1993, but it seems it's a mistake... isn't it ?