Oracle PL/SQL程序设计 实验六

实验内容

以bs用户登录BOOKSALES数据库，利用PL/SQL程序编写下列功能模块。
SQL>CONN bs/bs@booksales

（1）创建一个函数，以客户号为参数，返回该客户订购图书的价格总额。

create or replace function sumprice(     id customers.customer_id%type) return books.cost%type     as     sumprice books.cost%type;     begin     select sum(quantity*cost) into sumprice from customers,books,orders,orderitem     where customers.customer_id = orders.customer_id and orders.order_id = orderitem.order_id and orderitem.isbn = books.isbn and customers.customer_id = id; return sumprice;    exception      when no_data_found then        dbms_output.put_line('the id is invaild!');    end sumprice; / 

（6）创建一个存储过程，输出不同类型图书的数量、平均价格。

 create or replace procedure books_msg     as     books_count orderitem.quantity%type;     begin       for emp in ( select title,ISBN,cost from books     )     loop     select sum(quantity) into books_count from orderitem where ISBN=emp.ISBN;        dbms_output.put_line(emp.title||'  单价：'||emp.cost||'  数量：'||books_count);        end loop;    end books_msg; / 

（18）创建一个触发器，禁止客户在非工作时间（早上8：00之前，晚上17：00之后）下订单。

CREATE OR REPLACE TRIGGER trg_orderitem     BEFORE INSERT OR UPDATE OR DELETE ON orderitem     BEGIN IF TO_CHAR(SYSDATE,'HH24:MI') NOT BETWEEN '08:00' AND '17:00' OR TO_CHAR(SYSDATE,'DY','NLS_DATE_LANGUAGE=AMERICAN') IN ('SAT','SUN') THEN RAISE_APPLICATION_ERROR(-20005,'只能在正常的时间内进行改变。'); END IF; END trg_orderitem; / 

检查

调用函数看结果；

declare     sprice books.cost%type;     begin     sprice:=sumprice(1);     dbms_output.put_line('价格'||sprice);     exception     when no_data_found then     dbms_output.put_line('not found');     end; / 

执行存储过程看结果；

触发触发器看结果

insert into orderitem values('1000','1','978-7-121-18619-8','5');