Question

我正在尝试添加删除级联，以便满足以下规则... •如果帐户持有人被删除，则必须删除属于该帐户持有人的所有帐户。

我收到错误，因为没有匹配的唯一密钥＆＃39;和＆＃39;无效的标识符＆＃39;

CREATE table ACCOUNT_HOLDER
( Cust_ID Number (5) CONSTRAINT pk_custID PRIMARY KEY,
Birthday Date, 
Gender Char (1) CONSTRAINT ck_gender CHECK (Gender IN ('M','F')),
Street varchar2 (20),
ZipCode Number (5),
City varchar2 (30),
Email varchar2 (30), CONSTRAINT fk_email FOREIGN KEY (email) REFERENCES Customer (email),
CONSTRAINT ck_email UNIQUE (Email));

CREATE table ACCOUNT
( Account# Number (5) CONSTRAINT pk_account PRIMARY KEY,
Payment_type varchar2 (15) CONSTRAINT ck_payment CHECK (Payment_type in ('Cash', 'Check', 'Credit', 'Debit')),
Date_created Date,
Cust_ID Number (5));

ALTER table ACCOUNT_HOLDER
ADD CONSTRAINT fk_account FOREIGN KEY (Account#) REFERENCES ACCOUNT (Account#) ON DELETE CASCADE;

Answer 1

级联外键必须放在依赖数据上。在这种情况下，ACCOUNT必须使用外键而不是ACCOUNT_HOLDER 通常，在依赖表中索引级联外键列也是一个好主意下面是修订版本，在SQLPlus中有示例删除（我向客户注释了外键，因为该表不在示例中）

CREATE TABLE ACCOUNT_HOLDER
(
  CUST_ID  NUMBER(5) CONSTRAINT PK_CUSTID PRIMARY KEY,
  BIRTHDAY DATE,
  GENDER   CHAR(1) CONSTRAINT CK_GENDER CHECK (GENDER IN ('M', 'F')),
  STREET   VARCHAR2(20),
  ZIPCODE  NUMBER(5),
  CITY     VARCHAR2(30),
  EMAIL    VARCHAR2(30),
  --   CONSTRAINT fk_email FOREIGN KEY (email) REFERENCES Customer (email),
  CONSTRAINT CK_EMAIL UNIQUE (EMAIL)
);

CREATE TABLE ACCOUNT
(
  ACCOUNT#     NUMBER(5) CONSTRAINT PK_ACCOUNT PRIMARY KEY,
  PAYMENT_TYPE VARCHAR2(15) CONSTRAINT CK_PAYMENT CHECK (PAYMENT_TYPE IN ('Cash', 'Check', 'Credit', 'Debit')),
  DATE_CREATED DATE,
  CUST_ID      NUMBER(5) REFERENCES ACCOUNT_HOLDER (CUST_ID) ON DELETE CASCADE
);

CREATE INDEX ACCOUNT_ACCOUNT_HOLDER_FKI
  ON ACCOUNT (CUST_ID);

以下是SQLPlus中的示例级联：

SQL> INSERT INTO ACCOUNT_HOLDER (CUST_ID, BIRTHDAY, GENDER, STREET, ZIPCODE, CITY, EMAIL) VALUES
  (1, SYSDATE, 'F', NULL, NULL, NULL, 'abc@123.net');  2  

1 row created.

SQL> 
SQL> INSERT INTO ACCOUNT_HOLDER (CUST_ID, BIRTHDAY, GENDER, STREET, ZIPCODE, CITY, EMAIL) VALUES
  (2, SYSDATE, 'M', NULL, NULL, NULL, '123@abc.net');  2  

1 row created.

SQL> INSERT INTO ACCOUNT (ACCOUNT#, PAYMENT_TYPE, DATE_CREATED, CUST_ID) VALUES
  (1, 'Debit', SYSDATE, 1);  2  

1 row created.

SQL> 
SQL> INSERT INTO ACCOUNT (ACCOUNT#, PAYMENT_TYPE, DATE_CREATED, CUST_ID) VALUES
  (2, 'Debit', SYSDATE, 1);  2  

1 row created.

SQL> INSERT INTO ACCOUNT (ACCOUNT#, PAYMENT_TYPE, DATE_CREATED, CUST_ID) VALUES
  (3, 'Debit', SYSDATE, 2);  2  

1 row created.

SQL> COMMIT;

Commit complete.

SQL> SELECT COUNT(*) FROM ACCOUNT;

  COUNT(*)
----------
         3

SQL> DELETE FROM ACCOUNT_HOLDER WHERE CUST_ID = 1;

1 row deleted.

SQL> SELECT COUNT(*) FROM ACCOUNT;

  COUNT(*)
----------
         1

尝试在SQL plus上删除级联

1 个答案: