PHP循环表Mysqli结果

I'm about month and a half into PHP. I tried to make function for fetching results from find_all_subjects():

      function find_all_subjects() {
       global $dbconnect;

       $q = "SELECT * FROM subjects ORDER BY id ASC";
       $subject_set = mysqli_query($dbconnect, $q);
       confirm_query($subject_set);
       return $subject_set;

      }

and then making a new function which will loop the result in table rows. The problem is it loops just one result... when I did it with <ul> and <li> it worked fine but it doesn't seem to work when doing it with the table. My table core tags are in another document. So it's not that...

function navigacija() {

               $s         = find_all_subjects();

          while($subjects = mysqli_fetch_assoc($s)) {  

               $out       = "<tr>";

               // Ime Teme

               $out      .= "<td width='25%' height='40'>&nbsp;&nbsp;<a href=\"admin_content.php?subject=" . urlencode($subjects['id']) . "\">";
               $out      .=  $subjects['menu_name'];
               $out      .= "</a></td>";

               // Vidljiva

           if($subjects['visible'] == 1) {
                  $subjects['visible'] = 'DA';
         } else {
                  $subjects['visible'] = 'NE';
         }
               $out      .= "<td width='25%' height='40'><p align=\"center\">DA&nbsp; / &nbsp;NE";
               $out      .= "</p></td>";

               // Broj Strana

               $out      .= "<td width='25%' height='40'>";

               $pages_set = find_sub_from_pages($subjects['id']);

             while($pages = mysqli_fetch_assoc($pages_set)) {  

               $out      .= "<a href=admin_content.php?page=" . $pages['id'] . ">" . $pages['menu_name'] . "</a>";
               $out      .= "</td>";

           }

               // Vidljiva

               $out      .= "<td align=\"center\" width='25%' height='40'>";
               $out      .= "<img width=\"17px\" height=\"17px\" src=\"st/img/ic-arup.png\">
                             </img>&nbsp;<img width=\"17px\" height=\"17px\" src=\"st/img/ic-ardown.png\"></img>&nbsp;";
               $out      .= "</td>";

               $out      .= "</tr>";
             }

              return $out;
 }

the problem is that you reset

 $out       = "<tr>";

every time in the loop. change this line to

$out       .= "<tr>";

and only put declaration out of the loop

$out       = "";