oracle - 从标识列的支持序列中获取 nextval

Question

我有一个这样声明的表列:

file_id number(10) generated always as identity primary key,

是否有可能以编程方式获得 currval/ nextval从它的支持序列而不实际查看 SYS。表来获取序列的名称，然后使用 execute immediate那个名字？

Answer 1

Is it possible to programatically get a currval/nextval from its backing sequence without actually looking into the SYS

是的，如果你真的需要这样做。您可以简单地在 USER_SEQUENCES 中查找该序列名称。数据字典 View ，或者更好 USER_TAB_IDENTITY_COLS数据字典 View ，并在您的查询中引用它。下面是一个例子:

create table t1(
  c1 number  generated always as identity primary key
);

insert into t1 values(default);

select *  from t1;

C1
-----
    1

就我而言，Oracle 为标识列创建的序列名称是 ISEQ$$_92984 .

select "ISEQ$$_92984".nextval from dual;

NEXTVAL
-------
     2

insert into t1 values(default);

select * from t1;

 C1
 ---------
         1
         3