Need a help in a query

Question

Table structure is given below …
Test_role
SC_CODE     VAR_NAME     FLD_NAME
SC1     Var1     NBR1
SC1     Var2     NBR2
SC2     Var3     NBR1
SC3     Var1     NBR1
SC3     Var4     NBR2
Test_role table contains some code and associated variable name like Var1, Var2, Var3 etc . The third column FLD_NAME  contains the column name of another table(Test_data) which contains actual value.
You can see here the field name NBR1 may not contain a particular variable always. It can vary for different  SC_CODE .
Test_data
CUST_ID     SC_CODE     NBR1     NBR2
1     SC1     10     20
2     SC2     50     
3     SC3     70     80
4     SC1     101     110
The above table contains CUST_ID which is mapped to SC_CODE of Test_role table.
Here CUST_ID  1 and 2  mapped to same variable SC1 but the actual value  for  cust_id=1 is (10,20) and  for 2 is (101,110)
I need a resulting table like test _result which will take all variable name as column , and populate the data accordingly. Resulting table data is given below.                                                        
Test_Result
CUST_ID     SC_CODE     VAR1     VAR2     VAR3     VAR4
1     SC1     10     20           
2     SC2                 50     
3     SC3     70                 80
4     SC1     101     102            Table script is given below ..
TEST_DATA
create table TEST_DATA
CUST_ID NUMBER(10),
SC_CODE VARCHAR2(50),
NBR1 NUMBER(5),
NBR2 NUMBER(5)
insert into TEST_DATA (CUST_ID, SC_CODE, NBR1, NBR2)
values (1, 'SC1', 10, 20);
insert into TEST_DATA (CUST_ID, SC_CODE, NBR1, NBR2)
values (2, 'SC2', 50, null);
insert into TEST_DATA (CUST_ID, SC_CODE, NBR1, NBR2)
values (3, 'SC3', 70, 80);
insert into TEST_DATA (CUST_ID, SC_CODE, NBR1, NBR2)
values (4, 'SC1', 10, null);
TEST_RESULT
create table TEST_RESULT
CUST_ID VARCHAR2(50),
SC_CODE VARCHAR2(50),
VAR1 NUMBER(5),
VAR2 NUMBER(5),
VAR3 NUMBER(5),
VAR4 NUMBER(5)
insert into TEST_RESULT (CUST_ID, SC_CODE, VAR1, VAR2, VAR3, VAR4)
values ('1', 'SC1', 10, 20, null, null);
insert into TEST_RESULT (CUST_ID, SC_CODE, VAR1, VAR2, VAR3, VAR4)
values ('2', 'SC2', null, null, 50, null);
insert into TEST_RESULT (CUST_ID, SC_CODE, VAR1, VAR2, VAR3, VAR4)
values ('3', 'SC3', 70, null, null, 80);
insert into TEST_RESULT (CUST_ID, SC_CODE, VAR1, VAR2, VAR3, VAR4)
values ('4', 'SC1', 101, 110, null, 80);
test_role
create table TEST_ROLE
SC_CODE VARCHAR2(50),
VAR_NAME VARCHAR2(50),
FLD_NAME VARCHAR2(50)
insert into TEST_ROLE (SC_CODE, VAR_NAME, FLD_NAME)
values ('SC1', 'Var1', 'NBR1');
insert into TEST_ROLE (SC_CODE, VAR_NAME, FLD_NAME)
values ('SC1', 'Var2', 'NBR2');
insert into TEST_ROLE (SC_CODE, VAR_NAME, FLD_NAME)
values ('SC2', 'Var3', 'NBR1');
insert into TEST_ROLE (SC_CODE, VAR_NAME, FLD_NAME)
values ('SC3', 'Var1', 'NBR1');
insert into TEST_ROLE (SC_CODE, VAR_NAME, FLD_NAME)
values ('SC3', 'Var4', 'NBR2');
Please help , if it can be done

Answer 1

Hi,
The script below is one example of how to do a pivot:
--     How to Pivot a Result Set (Display Rows as Columns)
--     For Oracle 10, and earlier
--     Actually, this works in any version of Oracle, but the
--     "SELECT ... PIVOT" feature introduced in Oracle 11
--     is better.  (See Query 2, below.)
--     This example uses the scott.emp table.
--     Given a query that produces three rows for every department,
--     how can we show the same data in a query that has one row
--     per department, and three separate columns?
--     For example, the query below counts the number of employess
--     in each departent that have one of three given jobs:
PROMPT     ==========  0. Simple COUNT ... GROUP BY  ==========
SELECT     deptno
,     job
,     COUNT (*)     AS cnt
FROM     scott.emp
WHERE     job     IN ('ANALYST', 'CLERK', 'MANAGER')
GROUP BY     deptno
,          job;
Output:
    DEPTNO JOB              CNT
        20 CLERK              2
        20 MANAGER            1
        30 CLERK              1
        30 MANAGER            1
        10 CLERK              1
        10 MANAGER            1
        20 ANALYST            2
PROMPT     ==========  1. Pivot  ==========
SELECT     deptno
,     COUNT (CASE WHEN job = 'ANALYST' THEN 1 END)     AS analyst_cnt
,     COUNT (CASE WHEN job = 'CLERK'   THEN 1 END)     AS clerk_cnt
,     COUNT (CASE WHEN job = 'MANAGER' THEN 1 END)     AS manager_cnt
FROM     scott.emp
WHERE     job     IN ('ANALYST', 'CLERK', 'MANAGER')
GROUP BY     deptno;
--     Output:
    DEPTNO ANALYST_CNT  CLERK_CNT MANAGER_CNT
        30           0          1           1
        20           2          2           1
        10           0          1           1
--     Explanation
(1) Decide what you want the output to look like.
     (E.g. "I want a row for each department,
     and columns for deptno, analyst_cnt, clerk_cnt and manager_cnt)
(2) Get a result set where every row identifies which row
     and which column of the output will be affected.
     In the example above, deptno identifies the row, and
     job identifies the column.
     Both deptno and job happened to be in the original table.
     That is not always the case; sometimes you have to
     compute new columns based on the original data.
(3) Use aggregate functions and CASE (or DECODE) to produce
     the pivoted columns. 
     The CASE statement will pick
     only the rows of raw data that belong in the column.
     If each cell in the output corresponds to (at most)
     one row of input, then you can use MIN or MAX as the
     aggregate function.
     If many rows of input can be reflected in a single cell
     of output, then use SUM, COUNT, AVG, STRAGG, or some other
     aggregate function.
     GROUP BY the column that identifies rows.
PROMPT     ==========  2. Oracle 11 PIVOT  ==========
WITH     e     AS
(     -- Begin sub-query e to SELECT columns for PIVOT
     SELECT     deptno
     ,     job
     FROM     scott.emp
)     -- End sub-query e to SELECT columns for PIVOT
SELECT     *
FROM     e
PIVOT     (     COUNT (*)
          FOR     job     IN     ( 'ANALYST'     AS analyst
                         , 'CLERK'     AS clerk
                         , 'MANAGER'     AS manager
NOTES ON ORACLE 11 PIVOT:
(1) You must use a sub-query to select the raw columns.
An in-line view (not shown) is an example of a sub-query.
(2) GROUP BY is implied for all columns not in the PIVOT clause.
(3) Column aliases are optional. 
If "AS analyst" is omitted above, the column will be called 'ANALYST' (single-quotes included).
{code}