tFPDF - 在 header 中显示 mySQL 个结果

tFPDF - Show mySQL results in header

我正在尝试在 tFPDF 的 header 中显示 mysql 的结果。到目前为止,我已经设法创建了 pdf,但是当我尝试添加要显示的 sql 数据时,出现错误。

我的代码:

...
$count = "SELECT
             SUM(app_price_out) AS Outcome,
             SUM(app_price_in) AS Income,
             SUM(app_price) AS Turnover
          FROM tblappointment";

foreach($connection->query($count) as $row) {
    $Outcome= $row['Outcome'];
    $Income= $row['Income'];
    $Turnover= $row['Turnover'];
}

$Total = $Income - $Outcome;
$Debt =  $Turnover - $Income;

class PDF extends tFPDF
{
// Page header
function Header()
{
   $this->SetLeftMargin(9);
   $this->AddFont('Calibri','','Calibri.ttf',true);
   $this->SetFont('Calibri','',9);
   $this->Cell(236,12,'Expenses',0,0);
   $this->Cell(18,6,'Total:',0,0,'R');
   $this->Cell(25,6,number_format($Total,0,",","."),0,0,'R');   ===> Error Line at $Total
   $this->Cell(18,6,'Debt:',0,0,'R');
   $this->Cell(25,6,number_format($Debt,0,",","."),0,0,'R');   ===> Error Line at $Debt
   $this->ln();
}
}
...

错误信息:

Notice: Undefined variable: Total in C:\xampp\...\page.php on line xx

CBroe 的帮助下,这是我的问题的解决方案。使用 global.

代码:

...
function Header()
{
   global $Total, $Debt;  
   $this->SetLeftMargin(9);
   ...