我可以在 Oracle 中创建两个相互调用的过程吗？

Can I make two procedures that call each other out in Oracle?

我有一个数据库来存储销售信息。我目前正在编写两个程序，一个用于插入有关销售的新详细信息，另一个用于更新现有的详细信息。如果用户想要插入一个已经存在的细节，我希望我的过程调用更新过程。同样，如果用户想要更新一个不存在的细节，我想调用插入过程。我插入新细节的代码如下：

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CREATE OR REPLACE PROCEDURE EX1.insert_detail
(id_sale IN INTEGER, id_product IN INTEGER, qty IN INTEGER)
IS
id_detail INTEGER;
mi_seq INTEGER;
u_price FLOAT;
BEGIN
BEGIN
SELECT detail.id_sales_order_detail INTO id_detail FROM EX1.sales_order_detail detail
WHERE detail.id_sales_order = id_sale AND detail.id_prod = id_product;
END;
IF id_detail IS NULL THEN
SELECT seq_sales_order_detail.NEXTVAL INTO mi_seq FROM dual;
SELECT prod.list_price INTO u_price FROM EX1.product prod;

INSERT INTO EX1.sales_order_detail VALUES
(mi_seq, id_sale, id_product, qty, u_price, EX1.calc_discount(qty, u_price));
BEGIN
EX1.update_costs(id_sale);
END;
ELSE
EX1.update_detail(id_sale, id_product, qty);
END IF;
END insert_detail;

要更新销售明细：

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CREATE OR REPLACE PROCEDURE EX1.update_detail
(id_sale IN INTEGER, id_product IN INTEGER, qty IN INTEGER)
IS
id_detail INTEGER;
BEGIN
BEGIN
SELECT detail.id_sales_order_detail INTO id_detail FROM EX1.sales_order_detail detail
WHERE detail.id_sales_order = id_sale AND detail.id_prod = id_product;
END;
IF id_detail IS NULL THEN
BEGIN
EX1.INSERT_DETAIL(id_sale, id_product, qty);
END;
ELSE
UPDATE EX1.SALES_ORDER_DETAIL
SET ORDER_QTY = ORDER_QTY + qty
WHERE ID_SALES_ORDER = id_sale AND id_prod = id_product;
BEGIN
EX1.update_costs(id_sale);
END;
END IF;
END update_detail;

我首先编译了每个过程，而没有调用另一个过程。完成此操作后，我重新编写了插入过程以调用更新过程。我编译了它，一切都很好。当我尝试在更新过程中调用插入过程时，问题就出现了。

我在编译时收到以下错误：ex1.insert_detail is invalid。但是，在编译 ex1.update_detail 之前，所有过程都是有效的。不知何故，让每个过程调用另一个过程会使它们都无效。

无论如何我能做到这一点吗？或者我应该只在每个过程中编写所有代码而不调用另一个？

在此问题上的任何帮助或指导将不胜感激。

问题是您在两个过程之间存在循环依赖关系。编译程序所依赖的对象会使该程序无效：循环依赖意味着您陷入了无效和重新编译的永久循环中。

一种解决方案是使用包。对象依赖于包规范，所以只要不改变我们就可以对包体做任何事情。

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CREATE OR REPLACE PACKAGE pkg_sales AS
PROCEDURE insert_detail(id_sale IN INTEGER, id_product IN INTEGER, qty );
PROCEDURE update_detail(id_sale IN INTEGER, id_product IN INTEGER, qty );
END pkg_sales;

然后你的身体可以像这样进行引用：

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CREATE OR REPLACE PACKAGE BODY pkg_sales AS

PROCEDURE insert_detail(id_sale IN INTEGER, id_product IN INTEGER, qty IN INTEGER)
IS
id_detail INTEGER;
mi_seq INTEGER;
u_price FLOAT;
BEGIN
BEGIN
SELECT detail.id_sales_order_detail INTO id_detail FROM EX1.sales_order_detail detail
WHERE detail.id_sales_order = id_sale AND detail.id_prod = id_product;
END;
IF id_detail IS NULL THEN
SELECT seq_sales_order_detail.NEXTVAL INTO mi_seq FROM dual;
SELECT prod.list_price INTO u_price FROM EX1.product prod;

INSERT INTO EX1.sales_order_detail VALUES
(mi_seq, id_sale, id_product, qty, u_price, EX1.calc_discount(qty, u_price));
BEGIN
EX1.update_costs(id_sale);
END;
ELSE
update_detail(id_sale, id_product, qty);
END IF;
END insert_detail;

PROCEDURE update_detail(id_sale IN INTEGER, id_product IN INTEGER, qty IN INTEGER)
IS
id_detail INTEGER;
BEGIN
BEGIN
SELECT detail.id_sales_order_detail INTO id_detail FROM EX1.sales_order_detail detail
WHERE detail.id_sales_order = id_sale AND detail.id_prod = id_product;
END;
IF id_detail IS NULL THEN
BEGIN
INSERT_DETAIL(id_sale, id_product, qty);
END;
ELSE
UPDATE EX1.SALES_ORDER_DETAIL
SET ORDER_QTY = ORDER_QTY + qty
WHERE ID_SALES_ORDER = id_sale AND id_prod = id_product;
BEGIN
update_costs(id_sale);
END;
END IF;
END update_detail;
END pkg_sales;

尽管如此，循环依赖仍然很糟糕。它指出了一个设计缺陷。更好的解决方案是有一个过程，procedure manage_detail(id_sale IN INTEGER, id_product IN INTEGER, qty IN INTEGER) 执行控制逻辑，并相应地决定是否调用插入或更新子例程。

或者，对于这种情况，有 MERGE 语句，它处理在纯 SQL 中是插入还是更新(或确实删除)。了解更多。

"am I better just writing the code to perform each procedure on its own"

可能不是。你最终会复制一些代码。模块化是一件好事，但最好是构建您的逻辑以避免循环依赖。除了其他任何事情之外，您还冒着无限递归的风险。

相关讨论

使用包：

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CREATE OR REPLACE PACKAGE TEST_CIRCULAR_REFERENCE
IS
PROCEDURE A( VALUE NUMBER );
PROCEDURE B( VALUE NUMBER );
END;
/

CREATE OR REPLACE PACKAGE BODY TEST_CIRCULAR_REFERENCE
IS
PROCEDURE A( VALUE NUMBER )
IS
BEGIN
DBMS_OUTPUT.PUT_LINE( 'A: ' || VALUE );
IF VALUE <= 1 THEN
NULL;
ELSIF MOD( VALUE, 2 ) = 0 THEN
A( VALUE / 2 );
ELSE
B( VALUE );
END IF;
END;

PROCEDURE B( VALUE NUMBER )
IS
BEGIN
DBMS_OUTPUT.PUT_LINE( 'B: ' || VALUE );
IF VALUE <= 1 THEN
NULL;
ELSIF MOD( VALUE, 2 ) = 0 THEN
A( VALUE );
ELSE
B( 3 * VALUE + 1 );
END IF;
END;
END;
/

所以你的包裹应该是这样的：

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CREATE OR REPLACE PACKAGE EX1.DETAILS
IS
FUNCTION get_detail_id ( id_product EX1.sales_order_detail.id_prod%TYPE )
RETURN EX1.sales_order_detail.id_sales_order_detail%TYPE;

PROCEDURE insert_detail(
id_sale IN EX1.sales_order_detail.id_sale%TYPE
id_product IN EX1.sales_order_detail.id_prod%TYPE,
qty IN EX1.sales_order_detail.id_qty%TYPE
);

PROCEDURE update_detail(
id_sale IN EX1.sales_order_detail.id_sale%TYPE
id_product IN EX1.sales_order_detail.id_prod%TYPE,
qty IN EX1.sales_order_detail.id_qty%TYPE
);
END;
/

你真的不需要两个程序。
只需用 MERGE 做一个。像下面这样的东西应该是一个好的开始；

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CREATE OR REPLACE PROCEDURE EX1.upd_ins_sales_detail(p_id_sale IN INTEGER, p_id_product IN INTEGER, p_qty IN INTEGER)
IS

BEGIN

MERGE INTO ex1.sales_order_detail sod
USING (SELECT exist_sod.id_sales_order_detail, exist_sod.id_prod, prod.list_price
FROM ex1.sales_order_detail exist_sod
INNER JOIN
ex1.product prod ON (prod.prod_id = exist_sod.prod_id)
WHERE exist_sod.id_sales_order = p_id_sale
AND exist_sod.id_prod = p_id_product
) upd
ON ( sod.id_sales_order_detail = upd.id_sales_order_detail)
WHEN MATCHED THEN UPDATE SET sod.qty = sod.qty + p_qty
WHEN NOT MATCHED THEN INSERT (mi_seq, id_sale, id_product, qty, u_price, EX1.calc_discount(qty, u_price))
VALUES (seq_sales_order_detail.NEXTVAL,
p_id_sale,
p_id_product,
upd.list_price,
EX1.calc_discount(p_qty, upd.list_price)

EX1.update_costs(id_sale);

COMMIT;

EXCEPTION
WHEN ..... THEN
put an EXCEPTION AS required here

END upd_ins_sales_detail;