make a field as foreign key of two tables in mysql code example

Example 1: mysql change foreign key

ALTER TABLE Orders
ADD FOREIGN KEY (PersonID) REFERENCES Persons(PersonID);

Example 2: alter table add column forigen key mysql

ALTER TABLE tryholpz_demo07.core_modules 
ADD COLUMN belongs_to_role INT, 
ADD FOREIGN KEY core_modules(belongs_to_role) REFERENCES role_specific_modules_info(id) ON DELETE CASCADE