Why can only output 5 element of the array

PHP
I have a list of student description as follow
input: array(ASIAN,EUPROPIAN,MIDDLE_EAST)
 
This is my table

Studentid        studentdescription
1                  ASIAN
2                  EUPROPIAN
3                  ASIAN
4                  EUPROPIAN
5                  ASIAN
6                  ASIAN  
7                  MIDDLE_EAST



foreach ($this->mapstudent as $student)
      {
  $query = "SELECT STUDENTID
             FROM STUDENT
             WHERE studentDescription = \"$student\"";

$result = mysql_query($query);
   
 $i = 0;
 while($row = mysql_fetch_array($result))
  {
      $this->splitstudentReturn[$i] = $row['studentID']; //get universeid and insert to GETCOMPNUM
   $i++;
  }
}

 print_r($this->splitstudentReturn)


i should get output = 1356247
but i only able got 5 element from array as show below

output      
Array ( [0] => 7 [1] => 4 [2] => 2 [3] => 6 [4] => 5 )

some more as you can see the result is reverse it start from
74265 --> why like that

why only five element show from array suppose should be 7 element