How to insert 2 queries with sequence in oracle?

Question

I have two queries:

INSERT INTO CLASS
(TEACHER_ID, CLASS,)
VALUES (:i_teacher_id, :i_class)
INSERT INTO TEACHER_INFO
(TEACHER_ID, TEACHER_NAME) VALUES (:i_teacher_id, :i_teacher_name)

teacher_id is incremented by sequence like this: t0001, t0002, t0003 ...etc

Then I tried to do it:

INSERT INTO TEACHER_INFO
(TEACHER_ID, TEACHER_NAME) VALUES (teacher_seq.nextval, :i_teacher_name)

But sequence give me just "4" not t0004

Answer 1

If teacher_id must be in this format, and must be constructed as part of the insert statement, you could do this:

INSERT INTO TEACHER_INFO 
(TEACHER_ID, TEACHER_NAME) 
VALUES ('t'||LPAD(teacher_seq.nextval, 4, '0'), :i_teacher_name)

That is, add the initial "t", then append the next sequence number after padding it out to 4 digits with zeroes.