问PHP和Mysql，我如何分组学生(每组3名学生)使用他们的CPGA分数？每一组必须有高、中、低的cgpa学生。

EN

SELECT * 
FROM students
ORDER BY cgpa DESC;

$grouped = [];
$group_count = intdiv(count($students), 3); //calculating number of groups
for($i=0;$i<$group_count;$i++){
   //loop group number times  
   $arr = []; // empty array
   $counter = $i;
   for($j=0;$j<3;$j++){
       //loop student number times in group
       array_push($arr, $students[$counter]);//add 3 student that has high, medium and low cgpa to array to create 1 group
       $counter+=$group_count;
   }
   array_push($grouped, $arr);// add created student group to new array
}