PHP代碼在提交之前執行

Question

我制作了一個登錄表單，但還有很多其他問題，現在我發現在提交 Submit 之前已執行了PHP代碼。 該如何解決？ 由於PHP不支持onclick事件（反正很爛！），所以我看不到任何已知的解決方案！

碼：

//Get the form with POST
$user = mysql_real_escape_string($_POST['user']);
$password = mysql_real_escape_string($_POST['pass']);



$usernames=mysql_query("SELECT * FROM user_info WHERE Username='" . $_POST['user'] . "' AND Password='" . $_POST['pass'] . "'");
if(!$usernames){echo mysql_error();}

$count=mysql_num_rows($usernames);
if(!$count){echo mysql_error();}

//If $count is equal to one, register the user and redirect him to his page, or else   echo him that his info is wrong
if($count === 1) {
$_SESSION['code'] = "titan";
$_SESSION['ande'] = $user;
$_SESSION['password'] = $password;
header("location: home.php");}
else {
echo "<p style='color:red;text-align:center;'>Wrong username or password!</p>";}

Answer 1

將應該在表單提交后執行的代碼包裝在IF語句中，該語句檢查是否提交了表單：

if ('POST' === $_SERVER['REQUEST_METHOD'])
{
    // your code goes here
}

Answer 2

檢查表格是否提交

if(isset($_POST['user'])) {

   //Your php code goes here

}

---

根據您的評論，我擴展了此答案

只需將所有代碼置於您在問題中發送的這種情況下

if(isset($_POST['user']))
{

    //Get the form with POST
    $user = mysql_real_escape_string($_POST['user']);
    $password = mysql_real_escape_string($_POST['pass']);



    $usernames=mysql_query("SELECT * FROM user_info WHERE Username='" . $_POST['user'] . "' AND Password='" . $_POST['pass'] . "'");
    if(!$usernames){echo mysql_error();}

    $count=mysql_num_rows($usernames);
    if(!$count){echo mysql_error();}

    //If $count is equal to one, register the user and redirect him to his page, or else   echo him that his info is wrong
    if($count === 1) {
    $_SESSION['code'] = "titan";
    $_SESSION['ande'] = $user;
    $_SESSION['password'] = $password;
    header("location: home.php");}
    else {
    echo "<p style='color:red;text-align:center;'>Wrong username or password!</p>";}

}

Answer 3

我沒有告訴你的是，PHP代碼與HTML表單和其余HTML文件在同一個文件中...我試圖用AJAX重新制作代碼，（（==無效，但還是有幫助！ ），為此，我將PHP代碼移到了另一個文件（ Login_engine.php ）中，就是這樣！當然，仍然存在一個小問題：現在，紅色文本顯示在Login_engine.php ... Login_engine.php ！