如何在 Oracle 的存储过程中对特定数量的项目实施最小和最大验证？

Question

我想添加一些验证，以便在我的存储过程中项目的最小数量大于或等于 2，而项目的最大数量小于或等于 10。如果项目小于 2 或大于 10，我希望显示一条错误消息并且不执行该过程。如果项目在验证范围内，则存储过程应正常执行。

CREATE OR REPLACE PROCEDURE insert_new_order
(
    p_order_id    IN ORDERS.ORDER_ID%TYPE, 
    p_order_num   IN ORDERS.ORDER_NUMBER%TYPE,
    p_name        IN ORDERS.BILLING_NAME%TYPE,
    p_email       IN ORDERS.BILLING_EMAIL%TYPE,
    p_address     IN ORDERS.BILLING_ADDRESS%TYPE,
    p_city        IN ORDERS.BILLING_CITY%TYPE,
    p_province    IN ORDERS.BILLING_PROVINCE%TYPE,
    p_postcode    IN ORDERS.BILLING_POSTCODE%TYPE,
    p_telephone   IN ORDERS.BILLING_TELEPHONE%TYPE, 
    p_total       IN ORDERS.BILLING_TOTAL%TYPE,
    p_order_date  IN ORDERS.ORDER_DATE%TYPE,
    p_items       IN ORDERS.ITEMS%TYPE
)
AS
BEGIN
    DBMS_OUTPUT.PUT_LINE ('Insert attempted');

    INSERT INTO orders (
      order_id,
      order_number,
      billing_name,
      billing_email,
      billing_address,
      billing_city,
      billing_province,
      billing_postcode,
      billing_telephone,
      billing_total,
      order_date,
      items
    ) VALUES (
      p_order_id,
      p_order_num,
      p_name,
      p_email,
      p_address,
      p_city,
      p_province,
      p_postcode,
      p_telephone,
      p_total,
      p_order_date,
      p_items
    );

    DBMS_OUTPUT.PUT_LINE ('Insert succeeded');

    EXCEPTION
     WHEN others THEN   
        DBMS_OUTPUT.PUT_LINE ('Insert rejected');
      DBMS_OUTPUT.PUT_LINE ('SQL Error Code:  ' || SQLCODE);
      DBMS_OUTPUT.PUT_LINE ('SQL Error Message:  ' || SQLERRM); 
      ROLLBACK;
END;
/

CREATE OR REPLACE TYPE order_item AS object(
    order_id INT, 
    product_id INT,
    seller_id INT, 
    sub_order_number CHAR(10),
    quantity INT, 
    condition CHAR(10),
    unit_price NUMBER, 
    cost_charge NUMBER,
    total NUMBER
);
/

CREATE OR REPLACE TYPE order_items AS Table of order_item;
/

 CREATE TABLE orders (
    order_id INT CONSTRAINT PKEY_order PRIMARY KEY,
    order_number CHAR(10),
    billing_name CHAR(100),
    billing_email CHAR(100),
    billing_address VARCHAR2(100),
    billing_city VARCHAR2(100),
    billing_province VARCHAR2(100),
    billing_postcode VARCHAR2(100),
    billing_telephone CHAR(25),
    billing_total NUMBER,
    order_date DATE,
    Items order_items)
    Nested Table Items Store As Orders_Item
  /

Answer 1

我希望这是一道作业题。如果这是一个真实的系统，那么有几件事是没有意义的——在真实的系统中为订单项目嵌套 table 会产生很大的问题，不允许恰好由单个项目组成的订单傻等

在您的程序中，您可以在程序的第一步检查集合中的元素数量并引发自定义错误

IF NOT( p_items.count BETWEEN 2 and 10 )
THEN
  RAISE_APPLICATION_ERROR( -20001, 'Orders must have between 2 and 10 items.  This order has ' || p_items.count );
END IF;

您几乎肯定想要删除异常处理程序。正如@MT0 指出的那样，仅调用 dbms_output.put_line 的 when others 异常处理程序存在很大问题。您不能假设任何人都会看到写入 dbms_output 缓冲区的消息——绝大多数真实系统不会对该文本执行任何操作。如果引发异常，事务将自动回滚。

如何在 Oracle 的存储过程中对特定数量的项目实施最小和最大验证？

How to implement minimum and maximum validation for a specific amount of items in a stored procedure in Oracle?

oracle

plsql

oracle11g