Question

我知道这是一个简单的修复，但我似乎无法弄清楚如何更改代码，所以我没有收到此错误：

ORA-00918：列模糊定义

以下是代码：

CREATE VIEW BOOK_INVENTORY (BRANCH_NUM, UNITS) AS    
SELECT BRANCH_NUM, ON_HAND 
FROM BRANCH, INVENTORY
WHERE BRANCH.BRANCH_NUM = INVENTORY.BRANCH_NUM
GROUP BY BRANCH.BRANCH_NUM
ORDER BY BRANCH.BRANCH_NUM;

提前感谢您的帮助。

Answer 1

我猜你需要指定你想要的BRANCH_NUM表：

CREATE VIEW BOOK_INVENTORY (BRANCH_NUM, UNITS) AS    
SELECT BRANCH.BRANCH_NUM, ON_HAND 
FROM BRANCH, INVENTORY
WHERE BRANCH.BRANCH_NUM = INVENTORY.BRANCH_NUM
GROUP BY BRANCH.BRANCH_NUM
ORDER BY BRANCH.BRANCH_NUM;

此外，您可能需要考虑使用后ANSI SQL-92语法进行连接：

CREATE VIEW BOOK_INVENTORY (BRANCH_NUM, UNITS) AS    
SELECT BRANCH.BRANCH_NUM, ON_HAND 
FROM BRANCH
INNER JOIN INVENTORY ON BRANCH.BRANCH_NUM = INVENTORY.BRANCH_NUM
GROUP BY BRANCH.BRANCH_NUM
ORDER BY BRANCH.BRANCH_NUM;

有关它的一些推理，请参阅Bad habits to kick : using old-style JOINs。

Answer 2

您正在制作SELECT BRANCH_NUM, ON_HAND而未确定哪些列来自哪些列。可能是其中一个存在于两个表中，例如将其修改为

SELECT INVENTORY.BRANCH_NUM, INVENTORY.ON_HAND 
-- ...

来自INVENTORY表内的那些列。）

Answer 3

CREATE VIEW BOOK_INVENTORY (BRANCH_NUM, UNITS) AS    
SELECT BRANCH.BRANCH_NUM, INVENTORY.ON_HAND 
FROM BRANCH, INVENTORY
WHERE BRANCH.BRANCH_NUM = INVENTORY.BRANCH_NUM
GROUP BY BRANCH.BRANCH_NUM, INVENTORY.ON_HAND 
ORDER BY BRANCH.BRANCH_NUM;

PS这个查询没有多大意义 - 为什么要分组？你也加入了两张表，没有明显的理由。这样做的唯一方法是排除无效的BRANCH

在SQL中创建视图并接收错误

3 个答案: