如何在插入新行时自动增加列中的值

首先,语法是 generated always always add

alter table demo
add sk integer generated always as (last_value(sk)+1);

失败原因:

ORA-30484: missing window specification for this function

last_value over (partition by xxx order by yyy) .不能将分析函数用作列默认值。

alter table demo
add sk integer generated always as identity;

create sequence sk_seq;

create or replace trigger demo_generate_sk_trg
before insert on demo for each row
begin
    :new.dummy := sk_seq.nextval;
end;
/