Question

我一直在使用这段代码，而且它一直运行良好，但现在我提出的查询只返回一个结果，突然$findproductsrow为NULL。我该如何解决这个问题？（第一个$ findproductsresult不为null，第二个是。）我是否需要添加一个子句，只返回一行？

$UserID = $_SESSION['userID'];
$findproductsstmt = mysqli_prepare($connection, "SELECT DISTINCT PID FROM prices WHERE UserID = ? and Manu = 0");
mysqli_stmt_bind_param($findproductsstmt, 'i', $UserID);
mysqli_stmt_execute($findproductsstmt);
$findproductsresult = mysqli_stmt_get_result($findproductsstmt);
if(mysqli_num_rows($findproductsresult) == 0) {
    echo('This user is not retailing any products.');
}
else{
    $findproductsrow = mysqli_fetch_array($findproductsresult, MYSQLI_ASSOC);
    var_dump($findproductsresult);
    while($findproductsrow = mysqli_fetch_array($findproductsresult, MYSQLI_ASSOC)){
        $_SESSION['PID'] = $findproductsrow['PID'];
        include '../includes/baseproductlist.php';
    }
}

Answer 1

您的问题出在ELSE声明中。

<强>问题

else{
    $findproductsrow = mysqli_fetch_array($findproductsresult, MYSQLI_ASSOC); // this pulls the first record, remove this
    var_dump($findproductsresult);
    while($findproductsrow = mysqli_fetch_array($findproductsresult, MYSQLI_ASSOC)){ // causing this to try and pull the second record which doesn't exist
        $_SESSION['PID'] = $findproductsrow['PID'];
        include '../includes/baseproductlist.php';
    }
}

<强>解决方案

else{
    while($findproductsrow = mysqli_fetch_array($findproductsresult, MYSQLI_ASSOC)){
        $_SESSION['PID'] = $findproductsrow['PID'];
        include '../includes/baseproductlist.php';
    }
}

mysqli_fetch_array vs mysqli_fetch_assoc

1 个答案: