Oracle Sequence

Question

I created a sequence and i am using a trigger on a field to generate the number, however there are existing number in the table that are within the sequence range
so i created to following code to look for existing numbers in the database then give a new sequence number. The sequence works fine but does not read the existing number in the database to give a new sequence number.
declare
v_pin_number_seq   varchar2(6);
CURSOR pin_no
   IS
   select pin_number from pin_request;
   pin_rec  pin_request.pin_number%type;
Begin
open pin_no;
fetch pin_no into pin_rec;
    SELECT PIN_NUMBER_SEQ.NEXTVAL
    INTO v_pin_number_seq
    FROM sys.dual;
     If v_pin_number_seq != pin_rec then
    :pin_number := v_pin_number_seq;
else
    SELECT PIN_NUMBER_SEQ.NEXTVAL
    INTO v_pin_number_seq
    FROM sys.dual;
End if;
   close pin_no;    
END;

Answer 1

Wrong forum, this is the Oracle Designer forum. You could ask this question inside the Oracle Database forum.
Not sure what you are trying to do? 
Do you have to re-sequence the table in the database? Or do you not want to prevent errors when the value of sequence exists inside the database,. You could also reset your sequence to the max value of the pin_number from the table.
The code above also does not loop over the table. It only checks the current value of the sequence against the current pin_number and it only increments the sequence once.