Help to write a query for cursor

Question

Hi
I have a table trans_table which has records for all Credit (C) and Debit(D) entries for customers with the trans_date.
Now there is a column adj_amt which contains 0 for all D entries. But for C entries it contains current trans_amt - Prev trans_amt. If there is no prev record with C type then it is 0. i.e. If this the first C entry for a particular account then adj_amt will contain 0.
Below is the data.
create table trans_table (cust_id number, tran_date date, tran_amt number, tran_type char(1), adj_amt number);
1 01/01/2007 100     D 0
1 01/01/2007 100     D 0
1 01/02/2007 80     C 0
1 05/02/2007 200     C 120
1 08/02/2007 300     C 100
2 01/01/2007 100     D 0
2 05/01/2007 100     D 0
2 08/01/2007 100     D 0
2 09/01/2007 100     D 0
2 01/02/2007 90     C 0
2 05/02/2007 200     C 110
3 01/01/2007 100     D 0
3 05/01/2007 100     D 0
3 08/01/2007 100     D 0
4 01/01/2007 100     D 0
4 05/01/2007 100     D 0
4 06/01/2007 100     D 0
4 08/01/2007 100     D 0
4 10/01/2007 100     D 0
4 01/02/2007 100     C 0                    
Now hv to write a query whioch gives the cust_id , max(tran_amt) with D entry, max(trans_amt) wth C entry and if no C entry record then this column will be 0.
The output wud be klike this..
1 100 300
2 100 200
3 100 0
4 100 100
Since cust_id 3 has no C entry so 0 value in 3rd column.
Now i wrote a query for cust_id and 2nd column, but am not able to get the 3rd column.
Is it possible to get the above output..
I wud be using this query in a cursor which wud fetch from 20 million transactions.
Thanks in advance
Piks
(I am pasting the insert script if required)
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (4, to_date('01-02-2007', 'dd-mm-yyyy'), 100, 'C', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (4, to_date('05-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (4, to_date('01-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (4, to_date('10-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (4, to_date('08-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (4, to_date('06-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (3, to_date('08-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (3, to_date('05-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (3, to_date('01-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (2, to_date('05-02-2007', 'dd-mm-yyyy'), 200, 'C', 110);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (2, to_date('01-02-2007', 'dd-mm-yyyy'), 90, 'C', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (2, to_date('05-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (2, to_date('01-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (2, to_date('09-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (2, to_date('08-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (1, to_date('08-02-2007', 'dd-mm-yyyy'), 300, 'C', 100);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (1, to_date('05-02-2007', 'dd-mm-yyyy'), 200, 'C', 120);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (1, to_date('01-02-2007', 'dd-mm-yyyy'), 80, 'C', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (1, to_date('01-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);
insert into TRANS_TABLE (CUST_ID, TRAN_DATE, TRAN_AMT, TRAN_TYPE, ADJ_AMT)
values (1, to_date('01-01-2007', 'dd-mm-yyyy'), 100, 'D', 0);

Answer 1

Hitherto an attempt:
test@ORA92>
test@ORA92> select * from trans_table;
   CUST_ID TRAN_DATE             TRAN_AMT T    ADJ_AMT
         4 02/01/2007 00:00:00        100 C          0
         4 01/05/2007 00:00:00        100 D          0
         4 01/01/2007 00:00:00        100 D          0
         4 01/10/2007 00:00:00        100 D          0
         4 01/08/2007 00:00:00        100 D          0
         4 01/06/2007 00:00:00        100 D          0
         3 01/08/2007 00:00:00        100 D          0
         3 01/05/2007 00:00:00        100 D          0
         3 01/01/2007 00:00:00        100 D          0
         2 02/05/2007 00:00:00        200 C        110
         2 02/01/2007 00:00:00         90 C          0
         2 01/05/2007 00:00:00        100 D          0
         2 01/01/2007 00:00:00        100 D          0
         2 01/09/2007 00:00:00        100 D          0
         2 01/08/2007 00:00:00        100 D          0
         1 02/08/2007 00:00:00        300 C        100
         1 02/05/2007 00:00:00        200 C        120
         1 02/01/2007 00:00:00         80 C          0
         1 01/01/2007 00:00:00        100 D          0
         1 01/01/2007 00:00:00        100 D          0
20 rows selected.
test@ORA92>
test@ORA92> select
  2    cust_id,
  3    max(case when tran_type = 'D' then tran_amt else 0 end) as max_c,
  4    max(case when tran_type = 'C' then tran_amt else 0 end) as max_d
  5  from trans_table
  6  group by cust_id;
   CUST_ID      MAX_C      MAX_D
         1        100        300
         2        100        200
         3        100          0
         4        100        100
4 rows selected.
test@ORA92>
test@ORA92>Cheers
pratz