Query to skip special customer numbers while auto generation

Question

Hi
I have a customer number maintenance screen refering table STTMS_CUSTOMER_SRNO_BANK, where customer number is auto generated.
Table:STTMS_CUSTOMER_SRNO_BANK columns are
CUSTOMER_RUNNING_NO , USED_FLAG
Present queries are:
SELECT MIN(customer_running_no)
INTO l_no
FROM sttms_customer_srno_bank
WHERE used_flag = 'N';
SELECT customer_running_no
INTO l_running_no
FROM sttms_customer_srno_bank
WHERE used_flag = 'N' AND customer_running_no = l_no
FOR UPDATE NOWAIT;
Current logic is it takes MIN(customer_running_no) and USED_FLAG is 'N'.
Now an enhancement is to be added that a new table CSTM_CUST_CATEGORY where a range of numbers is reserved for a special classification of customers.
Table:CSTM_CUST_CATEGORY
CUST_CATEGORY START_RANGE END_RANGE
ROYAL      1     100000
VIP 150000 200000
I need to write a query to auto generate customer numbers and the auto generated numbers should not fall in the special customer category like ROYAL,VIP,ie it should not be in the range 1-100000 and 150000-200000.
Please help me to write this query.
Thank you
Mary

Answer 1

Thanks a lot
This query works and serves half my requirement.
Ex..i have customer_running_no from 1300 to 1350 where used flag set to 'N'
and the start_range and end_range I have given is 1300 to 1500.
Now this query skips 1300 to 1350.It gives 1351.But my actual requirement is it should give 1501 as the next customer_running number.May I know what modification should i do to this query to get this expected result.