mysql参数化查询语句

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 准备SQL语句
$stmt = $conn->prepare("SELECT * FROM users WHERE username = ? AND password = ?");

// 绑定参数
$username = "admin";
$password = "password123";
$stmt->bind_param("ss", $username, $password);

// 执行查询
$stmt->execute();

// 获取结果
$result = $stmt->get_result();

// 处理结果
while ($row = $result->fetch_assoc()) {
    echo "ID: " . $row["id"] . " - 用户名: " . $row["username"] . "<br>";
}

// 关闭连接
$stmt->close();
$conn->close();
?>

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 准备SQL语句
$stmt = $conn->prepare("SELECT * FROM users WHERE username = :username AND password = :password");

// 绑定参数
$username = "admin";
$password = "password123";
$stmt->bindParam(':username', $username);
$stmt->bindParam(':password', $password);

// 执行查询
$stmt->execute();

// 获取结果
$result = $stmt->get_result();

// 处理结果
while ($row = $result->fetch_assoc()) {
    echo "ID: " . $row["id"] . " - 用户名: " . $row["username"] . "<br>";
}

// 关闭连接
$stmt->close();
$conn->close();
?>

if (!$stmt->execute()) {
    echo "执行查询时出错: " . $stmt->error;
}