更新创建视图 - 错误 ORA-01779：

Question

我已经使用 CREATE VIEW 命令创建了一个视图（很明显），并连接了多个表。 CREATE VIEW 命令运行良好，但是当我尝试更新 VIEW RentalInfoOct 时，我收到错误“ORA-01779：无法修改映射到非键保留表的列”

CREATE VIEW RentalInfoOct
(branch_no, branch_name, customer_no, customer_name, item_no, rental_date)
AS
SELECT i.branchNo, b.branchName, r.customerNo, c.customerName, i.itemNo, r.dateFrom
FROM item i
INNER JOIN rental r
ON i.itemNo = r.itemNo
INNER JOIN branch b
ON i.branchNo = b.branchNo
INNER JOIN customer c
ON r.customerNo = c.customerNo
WHERE r.dateFrom 
BETWEEN to_date('10-01-2009','MM-DD-YYYY')
AND to_date('10-31-2009','MM-DD-YYYY')

我的更新命令。

UPDATE RentalInfoOct
SET item_no = '3'
WHERE customer_name = 'April Alister'
AND branch_name = 'Kingsway'
AND rental_date = '10/28/2009'

我不确定这是否有助于解决问题，但这是我的 CREATE TABLE 命令

CREATE TABLE Branch
(
    branchNo    SMALLINT    NOT NULL,
    branchName  VARCHAR(20) NOT NULL,
    branchAddress   VARCHAR(40) NOT NULL,
    PRIMARY KEY (BranchNo)
);

--Item Table Definition
CREATE TABLE Item
(
    branchNo    SMALLINT    NOT NULL,
    itemNo      SMALLINT    NOT NULL,
    itemSize    VARCHAR(8)  NOT NULL,
    price       DECIMAL(6,2)    NOT NULL,
    PRIMARY KEY (ItemNo, BranchNo),
    FOREIGN KEY (BranchNo) REFERENCES Branch ON DELETE CASCADE,
        CONSTRAINT VALIDAMT
       CHECK (price > 0)
);

-- Customer Table Definition
CREATE TABLE Customer
(
    customerNo      SMALLINT    NOT NULL,
    customerName        VARCHAR(15) NOT NULL,
    customerAddress     VARCHAR(40) NOT NULL,
    customerTel         VARCHAR(10),
    PRIMARY KEY (CustomerNo)
);

-- Rental Table Definition
CREATE TABLE Rental
(
    branchNo    SMALLINT    NOT NULL,
    customerNo  SMALLINT    NOT NULL,
    dateFrom    DATE        NOT NULL,
    dateTo      DATE,
    itemNo      SMALLINT    NOT NULL,
    PRIMARY KEY (BranchNo, CustomerNo, dateFrom),
    FOREIGN KEY (BranchNo) REFERENCES Branch(BranchNo) ON DELETE CASCADE,
    FOREIGN KEY (CustomerNo) REFERENCES Customer(CustomerNo) ON DELETE CASCADE,
        CONSTRAINT CORRECTDATES CHECK (dateTo > dateFrom OR dateTo IS NULL) 
);

Answer 1

见：Oracle: multiple table updates => ORA-01779: cannot modify a column which maps to a non key-preserved table

您正在尝试使用连接更新视图，但连接条件不是基于唯一性约束，这会导致从一个表中的单行创建多行的可能性。

您的连接条件所基于的列之间似乎需要唯一键 - 外键关系。

编辑：我刚刚看到您的编辑。将r.branchNo = b.branchNo 更改为i.branchNo = b.branchNo 应该有很长的路要走。不确定r.customerNo = c.customerNo 的效果如何。