创建 MySQL 存储过程

Question

我尝试将一个使用SQL Plus的过程转换为MySQL，但是在第三行出现语法错误，即(W_IN IN NUMBER)，并且IN被标记为语法错误。

SQL Plus:

CREATE OR REPLACE PROCEDURE PRC_CUS_BALANCE_UPDATE (W_IN IN NUMBER) AS
W_CUS NUMBER := 0;
W_TOT NUMBER := 0;
BEGIN
-- GET THE CUS_CODE
SELECT CUS_CODE INTO W_CUS 
FROM INVOICE
WHERE INVOICE.INV_NUMBER = W_IN;

-- UPDATES CUSTOMER IF W_CUS > 0
IF W_CUS > 0 THEN
    UPDATE CUSTOMER
    SET CUS_BALANCE = CUS_BALANCE + 
                (SELECT INV_TOTAL FROM INVOICE WHERE INV_NUMBER = W_IN)
    WHERE CUS_CODE = W_CUS;
END IF;
END;

MySQL：

-- Trigger DDL Statements
DELIMITER $$

CREATE PROCEDURE prc_cus_balance_update (W_IN IN NUMBER) 
AS
W_CUS NUMBER = 0;
W_TOT NUMBER = 0;
BEGIN
-- GET CUS_CODE
SELECT CUS_CODE INTO W_CUS 
FROM INVOICE
WHERE INVOICE.INV_NUMBER = W_IN;

-- UPDATES CUSTOMER IF W_CUS > 0
IF W_CUS > 0 THEN
    UPDATE CUSTOMER
    SET CUS_BALANCE = CUS_BALANCE + 
                (SELECT INV_TOTAL FROM INVOICE WHERE INV_NUMBER = W_IN)
    WHERE CUS_CODE = W_CUS;
END IF;
END $$

DELIMITER ;

非常感谢任何帮助！

- Noah Jones

Answer 1

这在MySQL 5.5.23中可以编译：

-- Trigger DDL Statements
DELIMITER $$

DROP PROCEDURE IF EXISTS prc_cus_balance_update;

CREATE PROCEDURE prc_cus_balance_update (IN W_IN INT UNSIGNED) 
BEGIN
DECLARE W_CUS INT UNSIGNED DEFAULT 0;
DECLARE W_TOT DOUBLE DEFAULT 0; -- NOT USED?
-- GET CUS_CODE
SELECT CUS_CODE INTO W_CUS 
FROM INVOICE
WHERE INVOICE.INV_NUMBER = W_IN;

-- UPDATES CUSTOMER IF W_CUS > 0
IF W_CUS > 0 THEN
    UPDATE CUSTOMER
    SET CUS_BALANCE = CUS_BALANCE + 
                (SELECT INV_TOTAL FROM INVOICE WHERE INV_NUMBER = W_IN)
    WHERE CUS_CODE = W_CUS;
END IF;
END $$

DELIMITER ;

当然，在这种情况下，不需要存储过程，因为以下查询将更快地执行相同的功能（并且更易于理解）：

UPDATE 
    CUSTOMER c
INNER JOIN
    INVOICE i ON i.CUS_CODE = c.CUS_CODE
SET 
    c.CUS_BALANCE = c.CUS_BALANCE + i.INV_TOTAL 
WHERE 
    i.INV_NUMBER = W_IN

- Ross Smith II

---

在将$$指定为分隔符后，您必须将其作为Drop语句的结束语句。 - Abdul Saleem

@Ross Smith II，你能帮我解决我的问题吗？ - Nurav

Answer 2

这份文档似乎在说：

 [ IN | OUT | INOUT ] param_name type

- Alain Collins