php - 如何使用 PHP 验证表中的所有行

Question

下面是我尝试验证表中是否存在相同名称、id 和 email 的脚本，问题是即使我添加每个字段的新输入我仍然得到“数据已存在”，如何解决此问题，以及如何使用每个字段的正则表达式进行验证。对于 id 我需要使用正则表达式三个字母和 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>

以及如何验证字段是否具有相同的名称。例如，我有 3 个输入字段，在第一个字段中输入一个人的姓名，在第二个或第三个字段中，如果我输入相同的姓名，则当我单击提交按钮时应该显示错误，可以使用 for 来完成吗？循环检查每个字段是否包含相同的名称。

Answer 1

uuhm，您对这些变量是否已存在的行的检查没有使用任何变量？

$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 prepared statements 的更多信息

编辑:

基于注释的新查询，只需在 PHP 中检查 name/manager/senior 中的 double 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!');
    }
}