PHP 变量未在 while 循环中更新

Question

I am writing a small PHP script to generate a CSV file based on customer invoices. I'm noticing that on my echo line to generate the order, only $order_date is updating. The other variables aren't changing. If I echo $rowprops[1], I do see that I am walking the rowset correctly.

I don't know enough about PHP to spot my mistake.

if ($result_daterange_orders = mysqli_query($con, $query_daterange_orders))
{
echo "Date,Order #,Gross,VAT,Net,VAT registration notes";
while ($row = mysqli_fetch_row($result_daterange_orders)) {
    $order_id = $row[0];
$query_is_order_eu = "SELECT 1 from wp_postmeta WHERE post_id = " . $order_id . " AND meta_key = '_shipping_country' AND meta_value IN
(
'AT',
'BE',
'BG',
'CH',
'CY',
'CZ',
'DE',
'DK',
'EE',
'ES',
'FI',
'FR',
'GB',
'GR',
'HR',
'HU',
'IE',
'IT',
'LT',
'LU',
'LV',
'MT',
'NL',
'PL',
'PT',
'RO',
'SE',
'SI',
'SK',
'IM',
'MC'
)";
if ($result_is_order_eu = mysqli_query($con, $query_is_order_eu)) {
    if (mysqli_num_rows($result_is_order_eu) != 0) { /* Order is in EU */
        mysqli_free_result($result_is_order_eu);
        $properties_query = "SELECT meta_key, meta_value FROM wp_postmeta WHERE post_id = " . $order_id . " AND meta_key = '_wcpdf_invoice_date'
            OR meta_key = '_wcpdf_invoice_number' OR meta_key = '_order_tax' OR meta_key = '_order_shipping_tax'
            OR meta_key = '_order_total'";
        if ($result_properties = mysqli_query($con, $properties_query)) {
            if (mysqli_num_rows($result_properties) != 0) { /* We have properties */
            $order_date;
            $invoice_id;
            $gross;
            $vat_total = 0;
            $vat_calced = 0;
            $net;
            $vnotes = "";
            while ($rowprops = mysqli_fetch_row($result_properties)) {
                //echo $rowprops[1]; different every time
                if (strcmp($rowprops[0], "_wcpdf_invoice_number") === 0) 
                    $invoice_id = $rowprops[1]; 
                if (strcmp($rowprops[0], "_wcpdf_invoice_date") === 0)
                    $order_date = $rowprops[1];
                if (strcmp($rowprops[0], "_order_total") === 0)
                    $gross = $rowprops[1];
                if (strcmp($rowprops[0], "_order_tax") === 0) {
                    $vat_total += $rowprops[1];
                    $vat_calced +=1;
                }
                if (strcmp($rowprops[0], "_order_shipping_tax") === 0) {
                    $vat_total += $rowprops[1];
                    $vat_calced +=1;
                }
                if ($vat_calced == 2 && $vat_total === 0) /* VAT free customer */
                    $vnotes = "Order ID " . $order_id . " is VAT exempt. Registration number is "; 
                if ($vat_calced == 2 && $vat_total !== 0) /* Work out bottom line */
                    $net = $gross - $vat_total;
            }
            // Format: Date, Order #, Gross, VAT, Net, VAT reg notes //
            mysqli_free_result($result_properties);
            echo $order_date . "," . $invoice_id . "," . $gross . "," . "," . $vat_total . "," . $net . "," . $vnotes . "\n";   
            }
        }

    }
}
}
mysqli_free_result($result_daterange_orders);
}
mysqli_close($con);
?>

Thanks -- I'm not sure why only $order_date is updating. At first I was concerned that I was repeating the loop but if you check my commented echo, it prints a unique value every time.

Answer 1

Looks to me like you're echoing after the loop has been run through entirely, and therefore each iteration of fetch_row is not being echoed, only the last fetch.

Your outer loop is on order_date, so that will change because echo is inside that loop, while it remains outside the inner loop which is iterating through your other variable info.

while ($rowprops = mysqli_fetch_row($result_properties)) {
    if ()...
    if ()...
    //echo is inside this inner loop so vars will update with every iteration
    echo $order_date . "," . $invoice_id . "," . $gross . "," . "," . $vat_total . "," . $net . "," . $vnotes . "\n";   
}
mysqli_free_result($result_properties);

Answer 2

In this case, It's hard to say what exactly the problem is, as there are nested loops, and inner loop result depends on what data is posted to a method. Eg. $query_daterange_orders - is this variable always the same?

Try to break the problem into smaller parts. 1 - starting from line 1 - make sure that $query_daterange_orders is always the same. and then go deeper, checking results on the next line.