1.2.4.3.Foreign key

• 指向別的table的primary key

• 如果有別的table的欄位設定為此table為Foreign key, 則無法被刪除

  • 需要先刪除參考此table為Foreign key的table

Create table studentsbackup2 (id INT(11) auto_increment primary key, coursename VARCHAR(100) not null, student_id INT(11), foreign key (student_id) references studentsdetails(id));