how can i call field on sql2 ? with the foreign key $rt? please help me [duplicate]

This question already has an answer here:

• mysqli_fetch_array()/mysqli_fetch_assoc()/mysqli_fetch_row() expects parameter 1 to be resource or mysqli_result, boolean given 33 answers

this code

<?php
            $bulan_sekarang = date("m");
            $tahun_sekarang = date("Y");
            $sql = "SELECT * FROM tbl_rt";
            $count = mysqli_query($con,$sql);
            while($row = mysqli_fetch_array($count,MYSQLI_ASSOC)){
              $rt = $row['rt'];
              $id_rt = $row['id_rt'];
              echo '<tr><th>'.$rt.'</th>';
              $sql2 = "SELECT no_rt,tgl_pemohon,SUM(jumlah) AS jum FROM tbl_dataklg WHERE no_rt=$rt AND jk=1 AND DATE_FORMAT(tgl_pemohon,'%m')=$bulan_sekarang and DATE_FORMAT(tgl_pemohon,'%Y')=$tahun_sekarang";
              $hasil = $con->query($sql2);
              $hitung2 = $hasil->fetch_assoc();
              echo '<th>'.$hitung2['jum'].'</th>';
              echo '</tr>';
            }

Why i couldnt put fetch assoc on while? how can i call field on tbl_dataklg?