MYSQL MEHRERE FOREAIGN KEYS Erhalten Kann keine Fremdschlüsseleinschränkung hinzufügen

Question

CREATE TABLE customer ( 
    customer_id INT NOT NULL,  
    last_name VARCHAR(25) NOT NULL,  
    first_name VARCHAR(25) NOT NULL,  
    street_address VARCHAR(25) NOT NULL,  
    apt_number INT NULL,  
    city VARCHAR(20) NOT NULL,  
    state VARCHAR(2) NOT NULL,  
    zip_code INT NULL,  
    home_phone VARCHAR(12) NOT NULL,  
    mobile_phone VARCHAR(12) NULL,  
    other_phone VARCHAR(12) NULL,  
    PRIMARY KEY(customer_id)  
);  

CREATE TABLE donut_order(  
    donut_order_id INT NOT NULL,  
    customer_id INT NOT NULL,  
    order_date DATE NOT NULL,  
    special_handling_notes VARCHAR(255) NULL,  
    PRIMARY KEY(donut_order_id),  
    FOREIGN KEY (customer_id)  
    REFERENCES customer (customer_id)  
    ON DELETE CASCADE  
    ON UPDATE CASCADE 
); 

CREATE TABLE donut_order_item (  
    donut_order_id INT NOT NULL,  
    donut_id INT NOT NULL,  
    qty INT NOT NULL,  
    PRIMARY KEY(donut_order_ID, donut_id),  
    UNIQUE INDEX(donut_id, donut_order_id),  
    CONSTRAINT donut_order FOREIGN KEY (donut_order_id)  
    REFERENCES donut_order (donut_order_id)  
    ON DELETE RESTRICT  
    ON UPDATE RESTRICT, 

    CONSTRAINT donut FOREIGN KEY (donut_id)  
    REFERENCES donut (donut_id)  
    ON DELETE RESTRICT 
    ON UPDATE RESTRICT 
); 

Answer 1

Versuchen Sie stattdessen die Benutzeroberfläche zu verwenden, und es könnte Ihnen helfen, dieses Problem zu lösen. wie diese: