具有对象类型主键的PL/SQL
我创建对象关系类型如下具有对象类型主键的PL/SQL,sql,oracle,Sql,Oracle,我创建对象关系类型如下 CREATE OR REPLACE TYPE familycar_t AS OBJECT ( make VARCHAR (10), model VARCHAR(10), year NUMBER (4), fuel_type VARCHAR (10)); / CREATE OR REPLACE TYPE sedan_t AS OBJECT ( familycar ref familycar_t, cylinder_Size number(10)); / CREATE
CREATE OR REPLACE TYPE familycar_t AS OBJECT (
make VARCHAR (10),
model VARCHAR(10),
year NUMBER (4),
fuel_type VARCHAR (10));
/
CREATE OR REPLACE TYPE sedan_t AS OBJECT (
familycar ref familycar_t,
cylinder_Size number(10));
/
CREATE TABLE familycar OF familycar_t (PRIMARY KEY (make,model));
现在我想为“Sedan”表设置如下的主要参数
CREATE TABLE sedan OF sedan_t (PRIMARY KEY (familycar_t.make,familycar_t.model));
但是错误会像这样发生
从命令中的第4行开始出错-创建表sedan\u t
(主键(familycar\u t.make,familycar\u t.model))错误报告-SQL
错误:ORA-00904:“家庭卡”“MAKE”:无效标识符
90400000-%s:无效标识符
*原因:*行动:
解决方案是什么?您不能对类型为REF的属性创建索引(请参阅)。 如果REF的作用域为,则只能在REF属性或列上定义索引
CREATE OR REPLACE TYPE sedan_t AS OBJECT (
familycar familycar_t,
cylinder_Size number(10)
);
/
CREATE TABLE sedan OF sedan_t (PRIMARY KEY (familycar.make, familycar.model));
Table SEDAN created.
使用引用的替代方法是使用继承:
CREATE OR REPLACE TYPE familycar_t AS OBJECT (
make VARCHAR (10),
model VARCHAR(10),
year NUMBER (4),
fuel_type VARCHAR (10)
) NOT FINAL;
/
CREATE OR REPLACE TYPE sedan_t UNDER familycar_t (
cylinder_Size number(10)
);
/
CREATE TABLE familycar OF familycar_t (PRIMARY KEY (make,model));
CREATE TABLE sedan OF sedan_t (PRIMARY KEY (make,model));
但是,在这种情况下,您实际上不需要sedan
表:
INSERT INTO familycar
SELECT sedan_t( 'Ford', 'Model-T', 1908, 'Petrol', 4 ) FROM DUAL UNION ALL
SELECT familycar_t( 'Ford', 'Model-A', 1903, 'Petrol' ) FROM DUAL;
SELECT f.*,
TREAT( VALUE(f) AS sedan_t ).cylinder_size AS cylinder_size
FROM familycar f;
输出:
MAKE MODEL YEAR FUEL_TYPE CYLINDER_SIZE
---------- ---------- ---------- ---------- -------------
Ford Model-T 1908 Petrol 4
Ford Model-A 1903 Petrol (null)
您是否尝试过:
主键(familycar.make,familycar.model)
?也就是说,引用对象,而不是类型。我尝试了以下方法,但不正确。。。创建轿车的表轿车(主键(make%familycar,model%familycar));创建轿车的表轿车(主键(familycar.make%familycar\t,familycar.model%familycar\t));创建轿车的表轿车(主键(familycar.make%familycar\t,familycar.model%familycar\t));