基本Sql表

嘿，我正在设计一个虚构的银行数据库，我很难让所有的表和表之间的关系正常工作。 具体来说，我正试图在a2_bankbranch和a2_loan之间创建外键关系

我的代码在下面

CREATE TABLE a2_bank (
routing_code   VARCHAR(200)  PRIMARY KEY,
name          VARCHAR(200)  NOT NULL,
address       VARCHAR(200)  NOT NULL
);

INSERT INTO a2_bank VALUES
( '123456','ASB', '3 gladstone rd');
INSERT INTO a2_bank VALUES
( '123556','BNZ', '5 gladstone rd');
INSERT INTO a2_bank VALUES
( '12456','KIWIBANK', '3 gladstone rd');


CREATE TABLE a2_bankbranch (
name           VARCHAR(200)  NOT NULL,
branch_num     VARCHAR(200)  NOT NULL,
address        VARCHAR(200)  NOT NULL,
routing_code   VARCHAR(200)  NOT NULL,
total_loan     NUMBER(38),
FOREIGN KEY(routing_code) REFERENCES a2_bank(routing_code),
PRIMARY KEY(branch_num, routing_code)
);

INSERT INTO a2_bankbranch VALUES
( 'ASB', '5', '3 gladstone rd', '123456', '');
INSERT INTO a2_bankbranch VALUES
( 'ASB', '4', '28 stevee rd', '123456', '');

CREATE TABLE a2_loan (
loan_num       CHAR(10)  PRIMARY KEY,
type           VARCHAR(200)  NOT NULL,
amount         NUMBER(38)  NOT NULL,
contract_date  DATE          NOT NULL,
branch_num     VARCHAR(200) NOT NULL,
routing_code   VARCHAR(200) NOT NULL,
FOREIGN KEY(routing_code) REFERENCES a2_bank(routing_code),
FOREIGN KEY(branch_num) REFERENCES a2_bankbranch(branch_num)
);

INSERT INTO a2_loan VALUES
( '323', 'Mortgage', '2000000', TO_DATE('11-03-1994', 'DD-MM-YYYY'), '5', '123456' );
INSERT INTO a2_loan VALUES
( '33', 'Car', '2000', TO_DATE('12-08-1994', 'DD-MM-YYYY'), '5', '123456' );
INSERT INTO a2_loan VALUES
( '3243', 'Pesonal', '875', TO_DATE('14-06-1994', 'DD-MM-YYYY'), '5', '123456' );
INSERT INTO a2_loan VALUES
( '6', 'Mortgage', '400500', TO_DATE('11-06-1994', 'DD-MM-YYYY'), '5', '123456'  );

CREATE TABLE a2_account (
acc_num       CHAR(10)  PRIMARY KEY,
type           VARCHAR(20)  NOT NULL,
balance         VARCHAR(10)  NOT NULL
);
INSERT INTO a2_account VALUES
( '2539267332', 'Savings', '20');
INSERT INTO a2_account VALUES
( '8237893378', 'Cash', '300');
INSERT INTO a2_account VALUES
( '2378723936', 'Cheque', '75');
INSERT INTO a2_account VALUES
( '2378723937', 'Savings', '175');


CREATE TABLE a2_customer (
ird_num         CHAR(8)  PRIMARY KEY,
name            VARCHAR(200)  NOT NULL,
address         VARCHAR(200)  NOT NULL,
phone           VARCHAR(20)
);
INSERT INTO a2_customer VALUES
( '25362672',  'Stan Yel', '5 Wanna way', '02010201');
INSERT INTO a2_customer VALUES
( '83783783', 'Cam Birch', '34 Trada st', '02302020202');
INSERT INTO a2_customer VALUES
( '23723367', 'Jeff King', '5 Queens st', '38982383');
INSERT INTO a2_customer VALUES
( '54637822',  'John Smith', '24 Queen st', '38922383');


CREATE TABLE a2_accr (
ird_num                CHAR(8)  NOT NULL ,
account_num            CHAR(10)  NOT NULL,
FOREIGN KEY(ird_num) REFERENCES a2_customer(ird_num),
FOREIGN KEY(account_num) REFERENCES a2_account(acc_num)
);
INSERT INTO a2_accr VALUES
( '25362672', '2539267332');
INSERT INTO a2_accr VALUES
( '83783783', '8237893378');
INSERT INTO a2_accr VALUES
( '83783783', '2378723937');

CREATE TABLE a2_loanr (
ird_num                CHAR(8)  NOT NULL ,
loan_num            CHAR(10)  NOT NULL,
FOREIGN KEY(ird_num) REFERENCES a2_customer(ird_num),
FOREIGN KEY(loan_num) REFERENCES a2_loan(loan_num)
);
INSERT INTO a2_loanr VALUES
( '54637822', '323');
INSERT INTO a2_loanr VALUES
( '23723367', '33');

COMMIT;

我想我的外键在a2_贷款中出错了，但我不确定

我在a2_loan和a2_loanr表中遇到插入错误

---

如果您错误地引用了

外键
，我们将不胜感激

将
routingcode
列名更改为
routing\u code
，以与其他列名保持一致：

CREATE TABLE a2_bank (
    routing_code   VARCHAR(200)  PRIMARY KEY,
    name          VARCHAR(200)  NOT NULL,
    address       VARCHAR(200)  NOT NULL
 );

queery想要执行什么？举个例子，我只想创建表，但我遇到了插入错误，例如：插入a2_loan VALUES*第1行错误：ORA-00942：表或视图不存在。您无法插入，因为您正在为ird_num CHAR（8）插入值非空，loan_num CHAR（10） 不为NULL，但不插入外键。您可以告诉我如何修复此问题吗？我现在得到：外键（branch_num）引用a2_bankbranch（branch_num）*第9行错误：ORA-02270:此列列表没有匹配的唯一或主键您需要在
a2\u bankbranch
中创建
branch\u num
主键，请参见：