Need code for updating second record to first record in shell scripting

Hi,,

I have requirement that i need to get DISTINCT values from a table and if there are two records i need to update it to one record and then need to submit INSERT statements by using the updated value as a parameter. Here is the example follows..

SELECT DISTINCT ID FROM OFFER_GROUP WHERE OFFERS IN('A','B');

Result as follows

ID
1
11

Above statement always displays 1 or 2 records.If the above query returns 2 rows then i need to update it to 1 row like below

UPDATE OFFER_GROUP SET ID =1 WHERE OFFERS IN('A','B') AND ID =11;

And then i need to execute INSERT statements by using ID as a parameter.
whenever i use ${ID} it should be place with the updated value 1.

insert into <TABLE>values ();

For the above requirement, i need to implement it in shell scripting and i am using nzsql.

Thanks in advance.

Cheers,
Samah

Please help me out on this above requirement