Dynamic SQL Pivoting(Converting Row to Columns)

Question

Hi All,
I am using Oracle 9i (Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production)
and also 10g version
I am facing difficulties to find out the logic for
converting the set of values in one of the columns into the column headings for the entire query.
create TABLE my_tab ( deptno VARCHAR2(5), job VARCHAR2(50), sal NUMBER);
insert into my_tab ( deptno,JOB, sal) values ( 10, 'ANALYST', 23000);
insert into my_tab ( deptno,JOB, sal) values ( 10, 'SALESMAN', 1500);
insert into my_tab ( deptno,JOB, sal) values ( 10, 'CLERK', 3550);
insert into my_tab ( deptno,JOB, sal) values ( 20, 'SALESMAN', 700);
insert into my_tab ( deptno,JOB, sal) values ( 20, 'ANALYST', 4200);
insert into my_tab ( deptno,JOB, sal) values ( 30, 'SALESMAN', 5600);
insert into my_tab ( deptno,JOB, sal) values ( 30, 'CLERK', 12000);
insert into my_tab ( deptno,JOB, sal) values ( 30, 'ANALYST', 19000);
COMMIT;
SELECT * FROM my_tab
DEPTNO ______ JOB ________ SAL
10 ______ ANALYST ________ 23000
10 ______ SALESMAN     ________     1500
10     _______ CLERK     ________     3550
20     _______     SALESMAN ________     700
20     _______     ANALYST     ________ 4200
30     _______     SALESMAN ________     5600
30     _______     CLERK     _______          12000
30     _______ ANALYST     _______     19000
--And I wish to convert it into this structure:
DEPTNO ________ ANALYST ________ SALESMAN _________ CLERK
10      ________     23000 ________     1500     _________     3550
20     ________ 4200 ________     700     _________     NULL
30     ________ 19000 ________     5600     _________     12000
It may be dynamic. i.e Later i inserted more two records into My_tab.
insert into my_tab ( deptno,JOB, sal) values ( 20, 'CLERK', 3400);
insert into my_tab ( deptno,JOB, sal) values ( 30, 'MANAGER', 48000);
So it should be dynamic.
output is like this.
DEPTNO ________ ANALYST ______ SALESMAN ______ CLERK ______ MANAMGER
10           ________ 23000     ______ 1500     ______ 3550     ______     NULL
20          ________ 4200     ______ 700     ______ 3400     ______     NULL
30          ________ 19000     ______ 5600     ______ 12000     ______     48000
Please help me regarding this.
With warm regards,
Prasanta

Answer 1

Hi, Prasanta,
Displaying one column from many rows as many columns on one row is called Pivoting . The following thread shows the basics of how to pivot:
Help for a query to add columns
That example uses the aggregate COUNT function; you'll want SUM (or possibly MIN or MAX) instead.
Getting a dynamic number of columns requires Dynamic SQL . As a simpler alternative to pivoting and dynamic SQL, you might consider String Aggregation , where you concatenate a column from many rows into one big string, to be displayed on one row.
See the following thread for more about string aggregation and other options on pivoting into a variable number of columns:
Re: Report count and sum from many rows into many columns