Get the Status

Question

Hi everyone,
The solution for this might be simple but my brain is just too tired :(
I have this example table....
create table tmp_data(
tmp_data_id number,
tmp_data_date date,
tmp_data_id_request number,
tmp_data_status varchar2(50) );I have this example inserts....
insert into tmp_data values(1,SYSDATE, 100, 'INITIALIZED');
insert into tmp_data values(2,SYSDATE+1,100, 'PENDING APPROVAL');
insert into tmp_data values(3,SYSDATE+2, 100, 'APPROVED');
insert into tmp_data values(4,SYSDATE+3, 100, 'CONCLUDED');
insert into tmp_data values(5,SYSDATE, 101, 'INITIALIZED');The request is to show the data like this:
COL1...col2...............col3
100...INITIALIZED...10/04/2012
100...Changed from INITIALIZED->PENDING APPROVAL...10/04/2012
100..Changed from PENDING APPROVAL -> APPROVED...11/04/2012
100..Changed from APPROVED -> CONCLUDED...11/04/2012
101...INITIALIZED...10/04/2012P.S Oracle DB 11g

Answer 1

Try looking at using the LAG function...
e.g.
SQL> ed
Wrote file afiedt.buf
  1  select deptno, empno, ename, job, lag(job) over (partition by deptno order by empno) as prev_emps_job
  2  from emp
  3* order by deptno, empno
SQL> /
    DEPTNO      EMPNO ENAME      JOB       PREV_EMPS
        10       7782 CLARK      MANAGER
        10       7839 KING       PRESIDENT MANAGER
        10       7934 MILLER     CLERK     PRESIDENT
        20       7369 SMITH      CLERK
        20       7566 JONES      MANAGER   CLERK
        20       7788 SCOTT      ANALYST   MANAGER
        20       7876 ADAMS      CLERK     ANALYST
        20       7902 FORD       ANALYST   CLERK
        30       7499 ALLEN      SALESMAN
        30       7521 WARD       SALESMAN  SALESMAN
        30       7654 MARTIN     SALESMAN  SALESMAN
        30       7698 BLAKE      MANAGER   SALESMAN
        30       7844 TURNER     SALESMAN  MANAGER
        30       7900 JAMES      CLERK     SALESMANHave a go and see if you can work it out from that.
Edit: or alternatively people can just give you the answer so you don't learn for yourself. :/
Edited by: BluShadow on 10-Apr-2012 15:49