title: Create database relationship by MySQL Workbench
body: <p>I'm try to create a foreign key between tables by using MySQL Workbench. But I don't know why I can't tick the checkbox to select a field in order to map with another field in another table. Maybe it require both field has the same type (and other conditions??)
  So can you tell me the criteria to create relationship using foreign key and how to do it in MySQL Workbench?</p>