问PHP MYSQL如何自动向表中添加值

EN

$range = range('A', 'Z');
$quota = 100;
$quotaperclass = 25;

for ($x = 0; $x < $quota/$quotaperclass ; $x++) {
        // Automated Create Class
        $sql= "INSERT INTO class(class_id,class_name,prodi_name) values('A25$x','".$range[$x]."','TK')";

        $subquery = "select student_id from alocatedclass"; //Check student already in class 
        $sql = "SELECT * FROM student WHERE student.prodi_name='TK' and student.student_id not in ({$subquery}) ORDER by student.student_id ASC LIMIT $quotaperclass";
        $result = mysql_query($sql);
        while($data = mysql_fetch_array($result)){
            // Should insert data to every class
            $sql = "insert into alocatedclass(student_id,class_id) values ('$data[student_id]','A25$x')";
        }
    }

Create Class A
insert student 1
insert student 2
insert student 3
.....
insert student 25    

Create Class B
insert student 26
insert student 27
insert student 28
.....
insert student 50