CODEWITHSUNDEEP
mysql
programming noob
programming noob

Reputation: 31

MySQL can't add foreign key error

  CREATE TABLE People
(
    ID INT UNSIGNED AUTO_INCREMENT,
    Company_Name VARCHAR(256) NOT NULL,
    Predicted_Pos VARCHAR(20),
    PRIMARY KEY (ID),

);

INSERT INTO People VALUES (1, 'Shujun Li', '3rd');

CREATE TABLE Driver
(
    ID INT UNSIGNED AUTO_INCREMENT,
    First_name VARCHAR(256) NOT NULL,
    Last_name VARCHAR(256) NOT NULL,
    Car_make VARCHAR(256) NOT NULL,
    Car_model VARCHAR(256) NOT NULL,
    People_ID INT UNSIGNED,
    PRIMARY KEY (ID),   
    FOREIGN KEY(People_ID) REFERENCES People(ID)

);

INSERT INTO People VALUES (1, 'Shujun Li', 'bob', 'merc', 'benz', 1);

Upvotes: 0

Views: 50

Answers (1)

Asaph
Asaph

Reputation: 162851

You have some circular references in your schema. The People table depends on the Driver table and the Driver table depends on the People table. You can never insert a record into one of the tables without having a row in the other first, an impossible, chicken n' egg situation. There are other examples of circular references in your schema. Remove all circular references from your schema.

Upvotes: 3

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