Question

I am trying to add records into two tables below,

CREATE TABLE customer
(Custno     CHAR(3),
 Custname   VARCHAR(25) NOT NULL,
 Custstreet VARCHAR(30) NOT NULL,
 Custcity   VARCHAR(15) NOT NULL,
 Custprov   VARCHAR(3) NOT NULL,
 Custpcode  VARCHAR(6) NOT NULL,
 Disc       DECIMAL(3,1),
 Balance    DECIMAL(7,2),
 Credlimit  DECIMAL(5),
 Srepno     CHAR(3),
 CONSTRAINT pkcustno PRIMARY KEY (Custno),
 CONSTRAINT fksrepno FOREIGN KEY (Srepno) REFERENCES salesrep(Srepno)
);


CREATE TABLE orders
(Orderno   CHAR(5) UNIQUE NOT NULL,
 Orderdate DATE,
 Custno    CHAR(3) NOT NULL,
 CONSTRAINT fkordercust FOREIGN KEY (Custno) REFERENCES customer (Custno)
);

When adding like this,

INSERT INTO orders(Orderno, Orderdate, Custno) VALUES('14587','2011-11-09', '125' );
INSERT INTO orders(Orderno, Orderdate, Custno) VALUES('11547','2011-11-07', '125' );

I get, “Cannot add or update a child row: a foreign key constraint fails (sh.orders, CONSTRAINT fkordercust FOREIGN KEY (Custno) REFERENCES customer (Custno))
”
Is something wrong the table?

Answer 1

You do not have a customer with CustNo = '125'. Because of this, the Foreign key fails. You are trying to place an order for a non-existent customer, the DB throws an error.