如何从fetch_assoc

Question

我正在尝试将fetch_assoc（mysqli）的结果转换为字符串
，但出现错误

  

mysqli_result类的对象无法转换为字符串

我需要获取SELECT查询结果的整数，以便将此返回值传递给另一个函数。

$delay = getDelayRisorsa();
setMaintenancePreno($delay); // I get error here

function getDelayRisorsa()
{
    global $log,$conn;
    $queryDelay = "SELECT DelayPreno FROM room WHERE IDRoom = 4";
    $resDelay = $conn->query($queryDelay); //Eseguo Query SQL

    while($row = $resDelay->fetch_assoc()) 
    {
        $resultDelay = $row["DelayPreno"];
    }
    return $resDelay;
}

Answer 1

您返回错误的变量。返回$resultDelay

function getDelayRisorsa()
{
    global $log,$conn;
    $queryDelay = "SELECT DelayPreno FROM room WHERE IDRoom = 4";
    $resDelay = $conn->query($queryDelay); //Eseguo Query SQL

    while($row = $resDelay->fetch_assoc()) 
    {
        $resultDelay = $row["DelayPreno"];
    }
    return $resultDelay;
}