将自动增量主键添加到oracle中的现有表 [英] Add a auto increment primary key to existing table in oracle
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问题描述
我想向具有数据的现有表中添加新的自动增量主列.我该怎么办?
I want to add a new auto increment primary column to a existing table which has data. How do I do that?
我首先添加了一个列,然后尝试添加一个序列,此后,我迷失了如何插入该列并将其作为主键.
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.
推荐答案
假设您的表称为t1
,而主键称为id
首先,创建序列:
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;
然后创建一个触发器,该触发器在插入时递增:
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;
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