Question

我有以下脚本。

逻辑是它应该检查是否为每个sql查询返回任何结果，如果其中任何一个没有结果它应该触发最后的else子句，但是目前它没有。

我觉得逻辑上的某些东西是错的，但是无法弄清楚是什么。

<?php

// username and password sent from form
$MyUsername = $_POST['Username'];
$MyUsername = mysqli_real_escape_string($conn, $MyUsername);

$MyPassword = $_POST['Password'];

//check username in admin
$adminsql="SELECT * FROM Admin WHERE Email='$MyUsername'";
$adminresult=mysqli_query($conn, $adminsql);
echo mysqli_error($conn);

//check username in Companys
$companysql="SELECT * FROM Companys WHERE Email='$MyUsername'";
$companyresult=mysqli_query($conn, $companysql);
echo mysqli_error($conn);

//check username in drivers
$driversql="SELECT * FROM Drivers WHERE Email='$MyUsername'";
$driverresult=mysqli_query($conn, $driversql);
echo mysqli_error($conn);

//check username in recruitment
$recruitmentsql="SELECT * FROM Recruitment WHERE Email='$MyUsername'";
$recruitmentresult=mysqli_query($conn, $recruitmentsql);
echo mysqli_error($conn);

if ($adminresult){
    //User found check password against hash
    while($row = mysqli_fetch_array($adminresult)){
            if(password_verify($MyPassword, $row['PassHash'])){
            $_SESSION['user'] = $MyUsername;
            echo '<META HTTP-EQUIV="Refresh" Content="0; URL=admin.php">';  
            }else{
                echo "Invalid login, please check you username and password and try again";
            echo '<META HTTP-EQUIV="Refresh" Content="2; URL=index.php">';  
            }
    }
} 
if ($companyresult) {
    //User found check password against hash
    while($row = mysqli_fetch_array($companyresult)){
            if(password_verify($MyPassword, $row['PassHash'])){
            $_SESSION['user'] = $MyUsername;
            $_SESSION['userid'] = $row['ID'];
            echo '<META HTTP-EQUIV="Refresh" Content="0; URL=company.php">';
            }else{
                echo "Invalid login, please check you username and password and try again";
            echo '<META HTTP-EQUIV="Refresh" Content="2; URL=index.php">'; 
            }
    }
}
if ($driverresult) {
    //User found check password against hash
    while($row = mysqli_fetch_array($driverresult)){
            if(password_verify($MyPassword, $row['PassHash'])){
            $_SESSION['user'] = $MyUsername;
            $_SESSION['userid'] = $row['ID'];
            echo '<META HTTP-EQUIV="Refresh" Content="0; URL=driver.php">';
            }else{
                echo "Invalid login, please check you username and password and try again";
            echo '<META HTTP-EQUIV="Refresh" Content="2; URL=index.php">'; 
            }
    }
} 
if ($recruitmentresult){
    //User found check password against hash
    while($row = mysqli_fetch_array($recruitmentresult)){
            if(password_verify($MyPassword, $row['PassHash'])){
            $_SESSION['user'] = $MyUsername;
            $_SESSION['userid'] = $row['ID'];
            echo '<META HTTP-EQUIV="Refresh" Content="0; URL=recruitment.php">';
            }else{
                echo "Invalid login, please check you username and password and try again";
            echo '<META HTTP-EQUIV="Refresh" Content="2; URL=index.php">'; 
            }
    }
}else{
    echo "Invalid login, please check you username and password and try again";
    echo '<META HTTP-EQUIV="Refresh" Content="2; URL=index.php">'; 
}

?>

Answer 1

如果没有设置$ recruitmentresult，那么最后的其他内容只会触发，而不会设置任何内容。如果你得到一个带有无效密码的$ driverresult，它也可能会触发其他的$ recruitment。如果你想确保最后的else只触发，如果没有设置任何东西，将每个if更改为elseif（但保留第一个）。这是一个例子 - 我遗漏了其他代码来保持这个简短：

if ($adminresult){
} elseif ($companyresult) {
} elseif ($driverresult) {
} elseif ($recruitmentresult){
} else {
}

这可能不是唯一正在发生的事情，但这可能有助于解决问题的根源。

此外，在您进行测试时，您可以尝试更改元刷新代码以回显某些内容。使用//注释元刷新代码，以便稍后将其放回。这不是必需的，但我认为测试它并确定哪个刷新实际触发是非常困难的，因为在您有机会看到任何消息出现之前，刷新可能会让您离开当前页面。

Answer 2

如果结果为空，mysqli_query的结果不会返回false，只有在连接或查询中出现错误时才会返回false。因此，如果之前没有工作，您需要检查mysql_num_rows($result)或mysql_num_rows($result)>0之类的内容

if (mysql_num_rows($adminresult)){ // you may have to add > 0
  // do something
} elseif (mysql_num_rows($companyresult)) {
  // do something
} elseif (mysql_num_rows($driverresult)) {
  // do something
} elseif (mysql_num_rows($recruitmentresult)){
  // do something
} else {
  // do something else
}

Else子句不会触发检查mysql结果

2 个答案: