我已经收到了错误代码1452，我试图添加键到一个表中，以保持数据在其他表中不可用。我已经创建了表，可以使用已经输入的信息，但我想使数据库正确，所以我试图使用键。请参考下面的代码。

CREATE TABLE CUSTOMERS (
    CustID varchar(50) NOT NULL,
    Client_Name varchar(50) NOT NULL,
    Client_Address varchar(80) NOT NULL,
    PRIMARY KEY (CustID)
);

CREATE TABLE ORDERS (
    Order_ID VARCHAR(10) NOT NULL,
    Client_NameID varchar(50) NOT NULL,
    Dates varchar(10) NOT NULL,
    PRIMARY KEY (Order_ID),
    FOREIGN KEY (Client_NameID) REFERENCES CUSTOMERS(CustID)
);

SELECT * FROM CUSTOMERS;
SELECT * FROM ORDERS;

DESCRIBE Orders; /*Used to display the Table*/

ALTER TABLE ORDERS ADD Dates VARCHAR(10); /*Used to add columns into the table*/

ALTER TABLE ORDERS DROP COLUMN Date; /*Used to remove column from the table*/

INSERT INTO CUSTOMERS (CustID, Client_Name, Client_Address) VALUES 
    ('168', 'Coventry Building Services', 'Units 2-4, Binley Industrial Estate, CV3 2WL'), /*Used to insert values into the columns*/
    ('527', 'Allied Construction LTD', '34, Lythalls La Industrial Estate, NG18 5AH'),
    ('169', 'Ricoh Builds Ltd', 'Unit 12, Stoneleigh Park, CV8 2UV'),
    ('32', 'British Embassy in Tehran', '198 Ferdowski Avenue Tehran 11316-91144 Iran');

INSERT INTO ORDERS (Order_ID, Client_NameID, Dates) VALUES 
    ('CON-2237', 'Coventry Building Services', '2014-12-14'),
    ('CON-3664', 'Allied Construction LTD', '2015-01-16'),
    ('CON-2356', 'Ricoh Builds Ltd', '2015-02-12'),
    ('CON-1234', 'British Embassy in Tehran', '2015-04-16');

DELETE FROM ORDERS WHERE Client_Name='Coventry Building Services'; /*Used to delete specific 
data from the specific row and column wherever applicable*/

DROP TABLE CUSTOMERS;
DROP TABLE ORDERS;

下面是我尝试使用的表，所有这些表都有一个键，如果需要，可以将它们链接在一起
仅包含主键的customers表
包含主键和外键的orders表