Question

更新的对象DML：

UPDATE DEPARTMENTS d
SET d=NEW OBJ_DEPARTMENT(1, 'Information Technology')
WHERE d.OBJECT_VALUE=(
    SELECT VALUE(d)
    FROM DEPARTMENTS d
    WHERE ROWNUM=1
);

插入的对象DML：

INSERT INTO DEPARTMENTS d
VALUES(NEW OBJ_DEPARTMENT(1, 'Information Technology'));

删除对象DML：

DELETE FROM DEPARTMENTS d
WHERE d.OBJECT_VALUE=NEW OBJ_DEPARTMENT(1, 'Information Technology');

MERGE INTO的Object DML的语法是什么，其中目标是对象表，而源是嵌套的对象表？

CREATE OR REPLACE OBJECT TYPE OBJ_DEPARTMENT IS OBJECT(
    DEPARTMENT_ID INTEGER,
    DEPARTMENT VARCHAR2(2000)
);
/
CREATE TABLE DEPARTMENTS OF OBJ_DEPARTMENT(
    CONSTRAINT PK_DEPARTMENTS PRIMARY KEY(DEPARTMENT_ID)
);
/

Answer 1

创建一个新的OBJ_DEPARTMENT集合，在PL / SQL中填充它，并使用table运算符在SQL语句中访问该集合。

此示例显示现有行，信息技术，更改为Humand资源，以及插入新行Accounting。

INSERT INTO DEPARTMENTS d
VALUES(NEW OBJ_DEPARTMENT(1, 'Information Technology'));


CREATE OR REPLACE TYPE OBJ_DEPARTMENT_TAB IS TABLE OF OBJ_DEPARTMENT;
/

declare
    obj_departments obj_department_tab := obj_department_tab(
        obj_department(1, 'Human Resources'),
        obj_department(2, 'Accounting')
    );
begin
    merge into departments old_departments
    using
    (
        select * from table(obj_departments)
    ) new_departments
    on (old_departments.department_id = new_departments.department_id)
    when matched then update
        set old_departments.department = new_departments.department
    when not matched then insert
        values(new_departments.department_id, new_departments.department);
end;
/

select * from departments;

DEPARTMENT_ID   DEPARTMENT
-------------   ----------
1               Human Resources
2               Accounting

PL / SQL中MERGE INTO的对象DML

1 个答案: