我正在尝试了解对象关系技术并创建父类型:
CREATE OR REPLACE TYPE STUDENT
AS OBJECT(
FIO VARCHAR2(200),
Bday DATE,
Pas_Id NUMBER(20),
Address VARCHAR2(50))
NOT INSTANTIABLE
NOT FINAL;
孩子类型:
CREATE OR REPLACE TYPE BACH
UNDER STUDENT(
fieldOfStud varchar2(200),
Group_N number(4),
ege number(4),
GPA number(4),
MEMBER FUNCTION year_N RETURN NUMBER);
--тело типа бакалавр
CREATE OR REPLACE TYPE BODY BACH IS
MEMBER FUNCTION year_N RETURN NUMBER IS
BEGIN
IF SUBSTR(Group_N, 1, 1) BETWEEN 1 and 4 THEN
RETURN SUBSTR(Group_N, 1, 1);
END IF;
RETURN 0;
END;
END;
创建的表:
CREATE TABLE Students_Table(
SID NUMBER CONSTRAINT id_pk PRIMARY KEY,
stdt STUDENT
);
并插入数据。我 100% 确定它存在。我想更新表和更改组,例如,从 5231 到 6231:
update Students_Table st
set TREAT(stdt as maga).Group_N = TREAT(stdt as maga).Group_N+1000
where TREAT(stdt AS MAGA).Pas_Id = 241122
但得到错误
ORA-00927: missing equal sign