如何使用PHP验证表中的所有行

Question

下面是我试图验证表中是否存在相同名称， id和email的脚本，问题是，即使我为每个字段添加新输入，我仍然会得到“数据已经存在”，该怎么办我解决了这个问题，也解决了如何对每个字段使用正则表达式进行验证。 对于id我需要使用正则表达式的三个字母和3个数字。

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

    //Retrieve the field values from our registration form.
    $name = !empty($_POST['name']) ? trim($_POST['name']) : null;
    $ccode = !empty($_POST['id']) ? trim($_POST['id']) : null;
    $email = !empty($_POST['email']) ? trim($_POST['email']) : null;

    $sql = "SELECT COUNT(*) AS num FROM users";
    $stmt = $pdo->prepare($sql);

    $stmt->bindValue(':name', $name);
    $stmt->bindValue(':id', $id);
    $stmt->bindValue(':email', $email);

    $stmt->execute();

    $row = $stmt->fetch(PDO::FETCH_ASSOC);
    if($row['num'] > 0){
        die('The Data already exists!');
    } else {
        $sql = "INSERT INTO users (name, id, email) VALUES (:name, :id,   :email)";
        $stmt = $pdo->prepare($sql);
        $stmt->bindValue(':name', $name);
        $stmt->bindValue(':id', $id);
        $stmt->bindValue(':email', $email);
        $result = $stmt->execute();
        if ($result) {
            echo 'User aadded successfully!';
        }
   } 
}
<form action="sign.php" method="post">
<label for="name">Name</label>
<input type="text" id="name" name="name" required><br>
<label for="id">id</label>
<input type="text" id="" name="id" required><br>
<label for="email">Email</label>
<input type="email" id="email" name="email" required><br>
<input type="submit" name="register" value=" Click to Add"></button>
</form>

以及如何验证字段名称是否相同。 例如，我有3个输入字段，在第一个字段中输入一个人的名字，在第二个或第三个字段中，如果输入相同的名字，则单击“提交”按钮时会显示错误，可以使用for来完成。循环检查每个字段是否包含相同的名称。

Answer 1

你可以试试：-

$name = ($_POST['name']) ? $name = trim($_POST['name']) : $name='';

Answer 2

嗯，检查那些变量是否已经存在的行不使用任何变量？

$sql = "SELECT COUNT(*) AS num FROM users"; // Where are the variables?
$stmt = $pdo->prepare($sql);


$stmt->bindValue(':name', $name);
$stmt->bindValue(':id', $id);
$stmt->bindValue(':email', $email);

$stmt->execute();

您想要做的是：

$sql = "SELECT COUNT(*) AS num FROM users WHERE name = :name OR id = :id OR email = :email"; // Where are the variables?
$stmt = $pdo->prepare($sql);


$stmt->bindParam(':name', $name);
$stmt->bindParam(':id', $id);
$stmt->bindParam(':email', $email);

$stmt->execute();

我对使用PDO不太有经验。 我自己更喜欢MySQLi

您应该阅读有关准备好的语句的更多信息

编辑：

基于注释的新查询，只需在使用PHP之前检查name / manager / senior中的双打即可：

if($name != $manager && $manager != $senior && $name != $senior) {
    $sql = "SELECT COUNT(*) AS num FROM users WHERE (name = :name OR manager = :manager OR senior = :senior)";
    $stmt = $pdo->prepare($sql);


    $stmt->bindParam(':name', $name);
    $stmt->bindParam(':manager', $manager);
    $stmt->bindParam(':senior', $senior);

    $stmt->execute();
    // insert other stuff
} else {
    // insert error here
}

完整代码：

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

    //Retrieve the field values from our registration form.
    $name = !empty($_POST['name']) ? trim($_POST['name']) : null;
    $manager= !empty($_POST['manager']) ? trim($_POST['manager']) : null;
    $senior= !empty($_POST['senior']) ? trim($_POST['senior']) : null;

    if($name != $manager && $manager != $senior && $name != $senior) {
        $sql = "SELECT COUNT(*) AS num FROM users WHERE (name = :name OR manager = :manager OR senior = :senior)";
        $stmt = $pdo->prepare($sql);


        $stmt->bindParam(':name', $name);
        $stmt->bindParam(':manager', $manager);
        $stmt->bindParam(':senior', $senior);

        $stmt->execute();

        $row = $stmt->fetch(PDO::FETCH_ASSOC);
        if($row['num'] > 0){
            die('The Data already exists!');
        } else {
            $sql = "INSERT INTO users (name, manager, senior) VALUES (:name, :manager,   :senior)";
            $stmt = $pdo->prepare($sql);
            $stmt->bindParam(':name', $name);
            $stmt->bindParam(':manager', $manager);
            $stmt->bindParam(':senior', $senior);
            $result = $stmt->execute();
            if ($result) {
                echo 'User added successfully!';
            }
        }
    } else {
        die('Duplicate in name/manager/senior!');
    }
}

Answer 3

您需要更新以下查询行

$sql = "SELECT COUNT(*) AS num FROM users";
$stmt = $pdo->prepare($sql);

对此

$sql = "SELECT COUNT(*) AS num FROM users WHERE name = :name OR id = :id OR email = :email";
$stmt = $pdo->prepare($sql);