So basically, the users gonna input the students ID, first name, last name, teacher's first name and teacher's last name. I want to get the ID which is corresponding to the teacher's first and last name.
Here's My Code:
$get_teacher = mysqli_query($link, "SELECT id FROM teachers WHERE first_name = '$teacher_first_name' AND last_name = '$teacher_last_name'");
$get_teacher_arr = mysqli_fetch_array($get_teacher);
$result = mysqli_query($link, "INSERT INTO students (student_id, first_name, last_name, teacher_id) VALUES ('$student_id', '$first_name', '$last_name', '$get_teacher_arr[0]');");