如何将一个查询的结果传递到第二个查询并在一个表中显示结果？

Question

I am using Codeigniter and am trying to pass the results of one query into a second. I receive the error

"Fatal error: Cannot use object of type CI_DB_mysql_result as array".

Any suggestions would be appreciated. For my $truck_num query I am simply grabbing a list of trucks in a field called truck_num. I am then trying to pass those results into a query that does some calculations.

Controller ///////////

    function average_battery_life_by_truck() {

    $truck_num = $this->mhedash_model->select_truck();

    foreach($truck_num->result_array() as $row) {
    $array = $row['truck_num']; 
    $results[] = $this->mhedash_model->select_battery_life_truck($array);

    }

    $data['array'] = $results;

    $data['main_content'] = 'mhe/average_truck_bat';
    return $this->load->view('includes/template',$data);



}

View //////

<?php error_reporting (E_ALL ^ E_NOTICE); ?>

<p><h1></h1></p>


<FORM 
<></div>
<br />
<p><h4 id="date"></h4></p>
<h3></h3>
<table id="table" class="sortable">
<THEAD>
    <TR>
        <TH>Truck</TH>
        <TH>Average Hours</TH>

    </TR>
</THEAD>

<TBODY>
    <?php $count = 0; ?>
<?php foreach($array as $row): ?>

    <TR >
        <TD><?php echo $row['average_bat_life']; ?></TD>
        <TD><?php echo $row['truck_num']; ?></TD>

    </TR>
    <?php $count++; ?>

<?php endforeach;?>
</TBODY>

</table>

MODEL/////

    function select_truck() {
    mysql_select_db('battery');
    $this->table_name = 'truck';


    $truck_num = "SELECT 
                    truck_num
                  FROM 
                    truck
                  WHERE 
                    battery_type_id = '5'
                    or battery_type_id = '8'
                    or battery_type_id = '10'
                    or battery_type_id = '9'
                  ORDER BY truck_num
              ";

             return $this->db->query($truck_num);
}

function select_battery_life_truck($data) {
    mysql_select_db('battery');
    $this->table_name = 'truck_hours';
    $truck_num = $this->db->escape($data);


    /*This query takes the current row's metered hours and subtracts it with the previous row's metered hours.
    We then average out the time the battery was on the truck for the date range */


    $query = "SELECT 
                ROUND(AVG(metered_hours-b),2) average_bat_life,
                truck_num
              FROM   (SELECT
                        id,
                        metered_hours,
                        loc_id,
                            (SELECT MAX(metered_hours) 
                             FROM 
                                (SELECT @rownum:=@rownum+1 id, truck_hours.metered_hours,truck_hours.loc_id from truck_hours,truck, (SELECT @rownum:=0) r where truck_hours.loc_id = truck.loc_id and truck.truck_num = $truck_num and DATE_SUB(CURDATE(),INTERVAL 30 DAY) >= truck_hours.ctrl_date  ) a 
                                 WHERE a.metered_hours < t.metered_hours)b

                                 FROM 
                            (SELECT @rownum:=@rownum+1 id, truck_hours.metered_hours,truck_hours.loc_id from truck_hours,truck, (SELECT @rownum:=0) r where truck_hours.loc_id = truck.loc_id and truck.truck_num = $truck_num and DATE_SUB(CURDATE(),INTERVAL 30 DAY) >= truck_hours.ctrl_date ) AS t) c,
                            truck

              WHERE c.loc_id = truck.loc_id 
              ORDER BY average_bat_life";
    return $this->db->query($query);
}

Answer 1

In your second query you are not fetching data from database.

So you need to add fetch method

In your controller

foreach($truck_num->result_array() as $row) {
    $array = $row['truck_num']; 
    $result = $this->mhedash_model->select_battery_life_truck($array);
    foreach($result->result_array() as $row_data) {
         $results[] = $row_data; 
    }
    }
      $data['array'] = $results;
      $data['main_content'] = 'mhe/average_truck_bat';
      $this->load->view('includes/template',$data);