Как рассчитать сумму значений столбцов, используя MySQL и PHP?

Question

Как подсчитать сумму суммы баланса (имя поля bal_amt db), где status столбец равен null, и отобразить ее в конце таблицы Excel. Как рассчитать сумму в столбце mysql Пожалуйста, помогите мне сделатьэто

      <?php
      include_once('dbconnect.php');
      date_default_timezone_set('Asia/Dubai');
      $xls_filename = 'Report_'.date('d-m-Y').'.xls'; // Define Excel (.xls) file name


      $sql = "SELECT a.cusName as CustomerName, a.cusMob as CustomerMob, a.invoiceNo as InvoiceNo,
                    a.invoiceDate as InvoiceDate, a.SPH_right, a.CYL_right,
                    a.Axis_right, a.Prism_right,a.Add_right,
                    a.SPH_left, a.CYL_left, a.status,
                    a.Axis_left, a.Prism_left,a.Add_left, 
                    CONCAT_WS(',', IF(a.PD_right IS NULL OR a.PD_right = '', '0', a.PD_right), IF(a.PD_left IS NULL OR a.PD_left = '', '0', a.PD_left)) as PD_RL,
                    a.total_VAT as TotalVAT, a.bill_tot as BillTot,
                    a.adv_amt as AdvanceAmt, 
                    a.bal_amt as BalanceAmt,
                    b.itemsName as Items,b.rate as Rate, b.amt_vat as ItemVat,
                    ROUND(b.amt_vat + b.amount, 2) as Amount
                    FROM invoices a, invoice_items b where a.invoiceID=b.invoiceid and  a.status IS NULL
                    and a.invoiceDate between '$getfromdate' and '$gettodate' 
                    order by a.invoiceID desc";

      $result = mysqli_query($link, $sql);



      // Header info settings
      header("Content-Type: application/xls");
      header("Content-Disposition: attachment; filename=$xls_filename");
      header("Pragma: no-cache");
      header("Expires: 0");

      /***** Start of Formatting for Excel *****/
      // Define separator (defines columns in excel &amp; tabs in word)
      $sep = "\t"; // tabbed character
        $col_cnt = 0;
      // Start of printing column names as names of MySQL fields
      for ($i = 0; $i<mysqli_num_fields($result); $i++) {
        $field_info = mysqli_fetch_field($result);
        $col = "{$field_info->name}";
        echo $col . "\t";
         $col_cnt++;
      }
      print("\n");
      // End of printing column names

      // Start while loop to get data
      $row_cnt = 0;
      $tot_BalanceAmt = 0;
      while($row = mysqli_fetch_row($result))
      {
        $schema_insert = "";
        $tot_BalanceAmt +=$row['BalanceAmt'];
        for($j=0; $j<mysqli_num_fields($result); $j++)
        {
          if(!isset($row[$j])) {
            $schema_insert .= " ".$sep;
          }
          elseif ($row[$j] != "") {
            $schema_insert .= "$row[$j]".$sep;
          }
          else {
            $schema_insert .= "".$sep;
          }
        }
        $schema_insert = str_replace($sep."$", "", $schema_insert);
        $schema_insert = preg_replace("/\r\n|\n\r|\n|\r/", " ", $schema_insert);
        $schema_insert .= "\t";
        print(trim($schema_insert));
        print "\n";
         $row_cnt ++;
      }
      print "\n";

      $schema_insert = "";
      for($i=0;$i<$col_cnt-25;$i++)
      {
        $schema_insert .= " ".$sep;
      }
      $schema_insert .= "TOTAL BALANCE = ".$sep;
      $schema_insert .= $tot_BalanceAmt.$sep;
      $schema_insert = str_replace($sep."$", "", $schema_insert);
      $schema_insert = preg_replace("/\r\n|\n\r|\n|\r/", " ", $schema_insert);
      $schema_insert .= "\t";
      print($schema_insert);
      print "\n";


    ?>

I want to display total balance amount ``` db column name BalanceAmt ``` at end of the   excel sheet and result should be like this

    bal_amt       status

    1        

    1             cancelled

    3        

    4             cancelled

    0

    3

    0
    3

Total Balance amount : 10 (only need to calculate sum of bal_amt where status field null)

Answer 1

Вы должны добавить $ Col_cnt и $ row_cnt, чтобы проверить итоговую строку и итоговый столбец

Код:

// Start of printing column names as names of MySQL fields
  $col_cnt = 0;
  for ($i = 0; $i<mysqli_num_fields($result); $i++) {
    $field_info = mysqli_fetch_field($result);
    $col = "{$field_info->name}";
    echo $col . "\t";
    $col_cnt++;
  }
  print("\n");
  // End of printing column names

  $row_cnt = 0;
  $tot_BalanceAmt = 0;
  while($row = mysqli_fetch_assoc($result))
  {
    $schema_insert = "";
    $schema_insert .= $row['col_1'].$sep.$row['col_2'].$sep.$row['col_price'];
    $tot_BalanceAmt +=$row['col_price'];
    $schema_insert = str_replace($sep."$", "", $schema_insert);
    $schema_insert = preg_replace("/\r\n|\n\r|\n|\r/", " ", $schema_insert);
    $schema_insert .= "\t";
    print(trim($schema_insert));
    print "\n";
    $row_cnt ++;
  }

  $schema_insert = "";
  for($i=0;$i<$col_cnt-2;$i++)
  {
    $schema_insert .= " ".$sep;
  }
  $schema_insert .= "Total Amount".$sep;
  $schema_insert .= $tot_BalanceAmt.$sep;
  $schema_insert = str_replace($sep."$", "", $schema_insert);
  $schema_insert = preg_replace("/\r\n|\n\r|\n|\r/", " ", $schema_insert);
  $schema_insert .= "\t";
  print($schema_insert);
  print "\n";