PHP 验证仅验证表单中的第一个文本框

你需要用检查行扩展你的PHP脚本。所有这些加起来。如果达到某个数字，则所有字段都正确，如果不在不正确的字段上中止。这也可以在 JavaScript 中完成。将为您提供两种解决方案。

if ($_SERVER['REQUEST_METHOD'] == "POST") //only execute when a post is sent to register.php
{
    $username = $_POST['usernameTxt'];
    $password = sha1($_POST['passwordTxt']);
    $cnfrmPass = sha1($_POST['cnfrmPasswordTxt']);
    $email = $_POST['emailTxt'];
    $cnfrmEmail = $_POST['cnfrmEmailTxt'];
    $fName = $_POST['fNameTxt'];
    $lName = $_POST['lNameTxt'];    
    function validate()
    {
        global $username, $password, $cnfrmPass, $email, $cnfrmEmail;
        var index = 0;
        //start the check
        if (!empty($username) )
        {
            index++;
        }
        else
        {
            return "Username can't be empty";
        }
        if ( (!empty($password) && !empty($cnfrmPass) ) && $password === $cnfrmPass)
        {
            index++; //password and confirm password are not empty and equal to each other.
        }
        else
        {
            if (empty($password) || empty($cnfrmPass))
            {
                return "password can't be empty";
            }
            else
            {
                return "passwords do not match";
            }
        }
        if ( (!empty($email) && !empty($cnfrmEmail) ) && $email === $cnfrmEmail) //you also want to check if this is a correct e-mail 
        {
            index++; //email and email password are not empty and equal to each other.
        }
        else
        {
            if (empty($email) || empty($cnfrmEmail))
            {
                return "Email can't be empty";
            }
            else
            {
                return "emails do not match";
            }
        }
        return index;
    }
    $validated = validate();
    if (validated == 3)
    {
        //validation pans out --> continue.
        $query = dbConnect()->prepare("INSERT INTO usersInfo (Username, Password, Email, FirstName, LastName) VALUES (:username, :password, :email, :fName, :lName)");
        $query->bindParam(':username', $username);
        $query->bindParam(':password', $password);
        $query->bindParam(':email', $email);
        $query->bindParam(':fName', $fName);
        $query->bindParam(':lName', $lName);
        if($query->execute()){
            header('Location: signin.php');
        }else{
            $error = "ERROR!";
        }
    }
    else
    {
        $error = $validated;        
    }
}    

您还可以对此处阅读的输入使用 HTML5 验证：http://www.the-art-of-web.com/html/html5-form-validation/

解决方案 2 JavaScript

<script language="JavaScript">
function validateForm()
{
    var index = 0;
    function error(obj)
    {
        obj.className = "input_error";
        obj.setAttribute("validate", false);
        document.getElementsByTagName("h3")[0].innerHTML += obj.previousElementSibling.innerHTML + " can not be empty.<br/>";
        return false;
    }
    function good(obj)
    {
        index++;
        obj.className = "input_good";
        obj.setAttribute("validate", true);
    }
    document.getElementsByTagName("h3")[0].innerHTML = ""; //empty h3 tag with error info.
    var form = document.getElementsByName("regForm")[0].querySelectorAll("input"); //select all input elements from form
    //iterate them
    for (var i = 0; i < form.length; ++i)
    {
        //use swith to avoid infinite if and elsing
        switch (form[i].type) //check on type.
        {
            //remember all inputs have a label as previousElementSibling
            case 'text' :
                //normal text fields.
                //check if empty and contains normal characters (no !@#$), including all diacritics
                form[i].value.length > 0 ? good(form[i]) : error(form[i]);
            break;
            case 'password' :
                //password fields.
                //check if empty
                form[i].value.length > 0 ? good(form[i]) : error(form[i]);
                if (form[i].name == 'cnfrmPasswordTxt' && form[i].value.length > 0) //if password then check if matches other password
                {
                    if (form[i].value === form[i+1].value)
                    {
                        good(form[i]);
                    }
                    else
                    {
                        form[i].className = "input_error";
                        form[i].setAttribute("validate", false);
                        document.getElementsByTagName("h3")[0].innerHTML += "Passwords do not match<br/>"; //notify the user that the passwords do not match.
                    }
                }
            break;
            case 'email' :
                //email fields.
                //check if empty
                form[i].value.length > 0 ? good(form[i]) : error(form[i]);
                if (form[i].name == 'cnfrmEmailTxt' && form[i].value.length > 0) //if password then check if matches other password
                {
                    if (form[i].value === form[i+1].value)
                    {
                        good(form[i]);
                    }
                    else
                    {
                        form[i].className = "input_error";
                        form[i].setAttribute("validate", false);
                        document.getElementsByTagName("h3")[0].innerHTML += "Emails do not match<br/>"; //notify the user that the emails do not match.
                    }
                }
            break;                          
        }
    }
    if (index == 9)
    {
        document.getElementsByName("regForm")[0].submit(); //submit once validated.
    }
    else
    {
        return false;
    }
}
 </script>

更改提交按钮

<input type="button" name="submitBn" value="Submit" onclick="validateForm()" style="margin-top: 5px; margin-bottom:5px;"/>

添加此 CSS

<style type="text/css">
    .input_error {
        border: 1px solid red;
    }
    .input_good {
        border: 1px solid lime;
    }
</style>

好吧，最后我决定不添加Javascript，这似乎有点矫枉过正...我想也许只是让服务器验证它 - 也许它带来的安全问题较少？

无论哪种方式，这是我为修复它所做的：

//setting variables to use here
$error = "";
$username = $_POST['usernameTxt'];
$password = sha1($_POST['passwordTxt']);
$cnfrmPass = sha1($_POST['cnfrmPasswordTxt']);
$email = $_POST['emailTxt'];
$cnfrmEmail = $_POST['cnfrmEmailTxt'];
//checking for any empty values or incorrect values
if(empty($username) === true){
    $error = "Username cannot be empty";
}
if($password != $cnfrmPass){
    $error = "Passwords do not match";
}
if($email != $cnfrmEmail){
    $error = "Emails do not match";
}
//if no errors occur start the registration process
if(empty($error) === true){
    $selectQ = dbConnect()->prepare("SELECT `Username` FROM `usersInfo` WHERE `Username`=:username");
    //setting the variables to the query
    $selectQ->bindParam(":username", $username);
    $selectQ->execute(); //execute query
    $count = $selectQ->rowCount(); //see if the above query has found anyone
    if($count > 0){
        $error = "User already exists. Please try again.";   
    }else{
        //if no users found start the insert query
        $insertQ = dbConnect()->prepare("INSERT INTO usersInfo (Username, Password, Email) VALUES (:username, :password, :email)");
        //setting the variables to the query
        $insertQ->bindParam(':username', $username);
        $insertQ->bindParam(':password', $password);
        $insertQ->bindParam(':email', $email);
        if($insertQ->execute()){
            //if the insert query executed successfully redirect them
            //to the login in page.
            header('Location: signin.php');
        }else{
            //otherwise show this error.
            $error = "Query could not execute!";
        }
    }
}