SQL 使用 OBJECT 作为 ORDER 方法的参数

Question

我有一个名为 Employee 的类型，它有一个以 Employee 作为参数的 ORDER 方法。我创建了一个 Employee 表并插入了一些数据。我正在尝试使用 SELECT 测试此 ORDER 方法，但是我很难满足参数。这是我的代码

    CREATE OR REPLACE TYPE Employee AS OBJECT(
  EmpID           VARCHAR(15),
   eName           VARCHAR(30),
   ePhone          NUMBER,
   eAddress        VARCHAR(15),
   ePosition       VARCHAR(15),
   eHireDt         DATE,
   salary          NUMBER,
   ORDER MEMBER FUNCTION orderSalary (e Employee) RETURN NUMBER)
NOT FINAL;
/

CREATE OR REPLACE TYPE BODY Employee AS
   ORDER MEMBER FUNCTION orderSalary(e Employee) return number IS
   BEGIN
      IF(self.salary > e.salary) then
         return(1);
      ELSIF (self.salary < e.salary) then
         return(-1);
        ELSE
            return(0);
      END IF;
   END;
END;
/

CREATE TABLE Emp OF Employee (EmpID PRIMARY KEY)
OBJECT IDENTIFIER PRIMARY KEY;


insert into Emp values('001','kabir',6477732272,'Pharmacy','clerk','2016-03-28',2000);

这是给我带来麻烦的一行:

SELECT p.orderSalary(Employee s) FROM Emp p;

我需要做的就是测试这个方法以确保它有效，有什么方法可以创建一个 Employee 实例来用作参数，或者从 Emp 表中获取一行？谢谢!

Answer 1

SELECT p.orderSalary( VALUE( p ) ) FROM Emp p;

或者:

SELECT p.orderSalary( DEREF( REF( p ) ) ) FROM Emp p;

或者:

SET SERVEROUTPUT ON;
DECLARE
  e1 EMPLOYEE := NEW EMPLOYEE('001','kabir',6477732272,'Pharmacy','clerk',DATE '2016-03-28',2000);
  e2 EMPLOYEE := NEW EMPLOYEE('002','bob',1234567890,'Library','assistant',DATE '2016-03-07',1000);
BEGIN
  DBMS_OUTPUT.PUT_LINE( e1.orderSalary( e2 ) );
END;
/

更新 - 选择不同的行:

insert into Emp values('001','kabir',6477732272,'Pharmacy','clerk','2016-03-28',2000);
insert into Emp values('002','bob',1234567890,'Library','assistant',DATE '2016-03-07',1000);

SELECT e1.ename AS name1,
       e2.ename AS name2,
       e1.orderSalary( VALUE( e2 ) )
FROM   Emp e1
       CROSS JOIN Emp e2;

输出:

NAME1  NAME2  E1.ORDERSALARY(VALUE(E2))
------ ------ -------------------------
kabir  kabir                          0 
kabir  bob                            1 
bob    kabir                         -1 
bob    bob                            0