foreign case in create as statement code example
Example 1: how to connect database foreign key in mysql
CREATE TABLE products(
productId INT AUTO_INCREMENT PRIMARY KEY,
productName varchar(100) not null,
categoryId INT NOT NULL,
CONSTRAINT fk_category
FOREIGN KEY (categoryId)
REFERENCES categories(categoryId)
ON UPDATE CASCADE
ON DELETE CASCADE
) ENGINE=INNODB;
Example 2: mysql alter add foreign key
ALTER TABLE ordenes ADD ticket VARCHAR(50) NOT NULL;
ALTER TABLE ordenes ADD CONSTRAINT fk_ticket FOREIGN KEY (ticket) REFERENCES tickets(ticket);