在 PHP/MySQL 中使用 SELECT SUM WHERE

Question

我正在用 MySQL 学习 PHP 并尝试使用 SELECT SUM 得到第 'QuantityChecked' 列的总数，但只有 'Lot' ] 匹配然后显示它。在这种情况下，我提供了一些我正在使用的代码，如果我还需要定义这个问题或代码，请告诉我。我现在遇到的问题是 'Lot' 似乎没有从 qcapproval.php 转移到 qcapproval-exec.php 中，我从以下错误消息

未定义索引：qcapproval 中的批次-exec.php

下面的代码。

qcapproval.php

<form action="qcapproval-exec.php?id=<?php echo $row['id']; echo $row['Lot']; ?>" method="post">
            <input type="hidden" name="id" value="<?php echo $row['id']; ?>" />
            <input type="hidden" name="Lot" value="<?php echo $row['Lot']; ?>" />
            <input type="hidden" name="CheckedBy" value="<?php echo $_SESSION['CheckedBy']; ?>" />

qcapproval-exec.php

$conn = new mysqli(DB_SERVER, DB_USER, DB_PASSWORD, DB_NAME) or die('there was a problem connecting to the database' . mysql_error());
session_start();
if (isset($_POST['submit']))
{
$QuantityChecked= $_POST['QuantityChecked'];
$AnodThickness= $_POST['AnodThickness'];
$QtyPassed= $_POST['QtyPassed'];
$QtyFailed= $_POST['QtyFailed'];
$SealsChecked= $_POST['SealsChecked'];
$SealsPassed= $_POST['SealsPassed'];
$SealsFailed= $_POST['SealsFailed'];
$GraphicsChecked= $_POST['GraphicsChecked'];
$GraphicsPassed= $_POST['GraphicsPassed'];
$GraphicsFailed= $_POST['GraphicsFailed'];
$CheckedBy= $_POST['CheckedBy'];
$id = $_GET['id'];
$Lot = $_GET['Lot'];
// OR
// $id = $_POST['id'];

$sql = "UPDATE logs SET  QuantityChecked= '$QuantityChecked',
                         AnodThickness = '$AnodThickness',
                         QtyPassed = '$QtyPassed',
                         QtyFailed = '$QtyFailed', 
                         SealsChecked = '$SealsChecked',
                         SealsPassed = '$SealsPassed',
                         SealsFailed = '$SealsFailed',
                         GraphicsChecked = '$GraphicsChecked',
                         GraphicsPassed = '$GraphicsPassed', 
                         GraphicsFailed = '$GraphicsFailed',
                         CheckedBy = '$CheckedBy',
                         DateTimeChecked = now() 
                         WHERE id = $id ";
$conn->query($sql);

$result = mysqli_query($conn, "SELECT SUM(QuantityChecked) AS TotalQuantityChecked FROM logs WHERE Lot = $Lot");
$row= mysqli_fetch_assoc($result);
$sum= $row['TotalQuantityChecked'];
$conn->close();
}

echo $sum;
echo "Record Updated.";

我已进行编辑以反映新代码和对此问题的更改

Answer 1

您正在使用 POST 提交表单，因此隐藏元素的值将在 $_POST 中，而不是 $_GET。

$Lot = $_POST['Lot'];

在 PHP/MySQL 中使用 SELECT SUM WHERE

Using SELECT SUM WHERE in PHP/MySQL

php

mysql

select

sum

where