Get autocomplete list based on other dropdown option value selection

Question

I am new in Web Development. I am working when user select option from other dropdown menu then get list from database query then display in autocomplete field. This is repeating rows you can also see the Image, so we ware not working with ids.

<select class="form-control item_type" name="item_type[]" id="item_type" required>
<option value="">Select Item Type</option>
<option value="7">7</option>
<option value="6">6</option>
</select>
<input type="text" class="form-control tags" name="wo_description[]" style="width:100% !important" required>

jquery code

$(function() {
    var availableTags = [
    <?php
    $query = $this->db->query('SELECT field_id, attribute_id FROM material_attributes_fields WHERE field_title = "Part Name" ');
    if($query->num_rows()==1){
        $row = $query->row();   
        $sql = $this->db->query('SELECT material_fields_values.item_id, material_fields_values.field_value, material_items.item_number FROM material_fields_values,material_items 
                                WHERE material_fields_values.item_id = material_items.item_id AND attribute_id = '.$row->attribute_id.' AND field_id = '.$row->field_id.' ');
        if($sql->num_rows()>0){
            $count = 0;
            foreach($sql->result() as $rec){
                $value = str_replace('"','',$rec->field_value);
                $number = str_replace('"','',$rec->item_number);
                echo $count==0?'"'.$value.','.$number.'"':','.'"'.$value.','.$number.'"';
                //echo $count==0?'"'.$rec->field_value.','.$rec->item_number.'"':','.'"'.$rec->field_value.','.$rec->item_number.'"';   
            $count++;
            }
        }else{ echo 'No Part Avalaible'; }  
    }
    ?>
    ];
    $(document).on('focus', '.tags', function () { 
        $(this).autocomplete({
            source: availableTags
        });
    });
     
  });

I have tried from this link