Question

请考虑以下代码。我想阅读持有人阵列上的电子邮件，但是当我尝试访问$ holder ['email']时，它失败了。我想用数据库中的旧电子邮件检查新输入的电子邮件。这是代码：

$conn = mysqli_connect("localhost", "root", "" ,"note_db");
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
//echo "Connected successfully";

$email = $_REQUEST ['email'];
$pass = $_REQUEST ['pass'];
$result = mysqli_query($conn, "SELECT email FROM users");

$holder = array();

while($row = mysqli_fetch_array($result)){
$record = array();

$record ['email'] = $row['email'];
$holder [] =  $record;

}

if($holder['email'] == $email){
    echo "email was set before";
    return;
}
else{
    $sql = mysqli_query($conn,"INSERT INTO users VALUES ('$email', '$pass')") ;
    echo "email Inserted to DataBase";

}

mysqli_close($conn);

Answer 1

试试这个：

$conn = mysqli_connect("localhost", "root", "" ,"note_db");
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
//echo "Connected successfully";

$email = $_POST ['email'];
$pass = $_POST ['pass'];
$result = mysqli_query($conn, "SELECT email FROM users");

$holder = array();
while($row = mysqli_fetch_array($result)){
$holder [] =  $row;
}
foreach($holder as $val){
    if($val['email']==$email){
        echo "email was set before";
        return FALSE;
    }
    else{
         $sql = mysqli_query($conn,"INSERT INTO users VALUES ('$email', '$pass')") ;
         echo "email Inserted to DataBase";
    }
}


mysqli_close($conn);

Answer 2

使用以下代码

$conn = mysqli_connect("localhost", "root", "" ,"note_db");
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
//echo "Connected successfully";

$email = $_REQUEST ['email'];
$pass = $_REQUEST ['pass'];
$result = mysqli_query($conn, "SELECT email FROM users");

$holder = array();

while($row = mysqli_fetch_array($result)){
    $record = array();

    $record ['email'] = $row['email'];
    $holder [] =  $record;

}

foreach( $holder as $key => $hold){
     if($hold['email'] == $email){
        echo "email was set before";
        return;
     }else{
        $sql = mysqli_query($conn,"INSERT INTO users VALUES ('$email',  '$pass')") ;
        echo "email Inserted to DataBase";

     }
}

mysqli_close($conn);

Answer 3

因为$ holder [＆＃39; email＆＃39;]并不存在。 $ foo [] =＆＃34; bar＆＃34; //给你这个数组＆＃34;数组（[0] =＆gt;＆＃34; bar）＆＃34; 要获取$ foo中的所有电子邮件，您应该循环播放

编辑：就像@Shahid Ahmad的建议一样 foreach($holder as $h) { echo $h['email']; }

Answer 4

如果您只想查看是否已经收到电子邮件，那么您可以使用布尔标志获得相同的结果。另外，请考虑使用PDO或准备好的语句。此外，如果您将从$ _POST或$ _GET中获取值，则显式设置。

$conn = mysqli_connect("localhost", "root", "" ,"note_db");
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
//echo "Connected successfully";

$email = $_POST['email']; //Or $_GET
$pass = $_POST['pass'];  //Or $_GET
$result = mysqli_query($conn, "SELECT email FROM users");

$found = false; //Boolean to check if email is already taken

while($row = mysqli_fetch_array($result)) {
    if ($row['email'] == $email) { //If email exists in database
        $found = true;
        break;
    }
}

if ($found) { //If email exists in database
    echo "email was set before";
    return;
} else { //Email doesn't exist so inset, Consider using prepared statements
    $sql = mysqli_query($conn, "INSERT INTO users VALUES ('$email', '$pass')") ;
    echo "email Inserted to DataBase";
}

mysqli_close($conn);

读取数组内部

4 个答案: