make a sequence in oracle database

Question

How can I create a sequence, which has two parts one fixed characters part and another variable integer part like "LTR00001" and the next value in the sequence should be "LTR00002"

Answer 1

You cannot. Sequences are just integers.

But you can select a formatted string from the sequence

SELECT 'LTR' || to_char('09999', the_sequence.nextval) FROM DUAL;