How to use the keyword 'references' in MySQL?

Question

How is the references keyword used when creating a table?

Let's say I want to create two tables person and hobby and I want the hobby table id to reference the id of person?

person table - id - name  hobby - id - person_id - hobby_name 

How do I do that?

Answer 1

Create the hobby table similarly to this:

CREATE TABLE hobby (   id INT NOT NULL AUTO_INCREMENT,   person_id INT NOT NULL,   hobby_name VARCHAR(255),   PRIMARY KEY(id),   FOREIGN KEY(person_id) REFERENCES person(id)) 

Answer 2

Here is an example directly from MySQL website:

CREATE TABLE parent (id INT NOT NULL,                      PRIMARY KEY (id) ) ENGINE=INNODB;  CREATE TABLE child (id INT, parent_id INT,                     INDEX par_ind (parent_id),                     FOREIGN KEY (parent_id) REFERENCES parent(id)                     ON DELETE CASCADE ) ENGINE=INNODB;