Add a auto increment primary key to existing table in oracle
oracle
Solution
Say your table is called `t1` and your primary-key is called `id` First, create the sequence:
create sequence t1_seq start with 1 increment by 1 nomaxvalue;
Then create a trigger that increments upon insert:
create trigger t1_trigger
before insert on t1
for each row
begin
select t1_seq.nextval into :new.id from dual;
end;
Problem
I want to add a new auto increment primary column to a existing table which has data. How do I do that? I first added a column and then try to add a sequence after that, I lost how to insert and make that column as primary key.