使用表列PDO进行算术运算

// 连接到数据库
$dsn = "mysql:host=localhost;dbname=mydatabase";
$username = "username";
$password = "password";

try {
    $pdo = new PDO($dsn, $username, $password);
} catch (PDOException $e) {
    echo "数据库连接失败：" . $e->getMessage();
    exit;
}

// 执行算术运算
$num1 = 10;
$num2 = 5;

// 加法运算
$sql = "SELECT :num1 + :num2 AS sum";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(':num1', $num1, PDO::PARAM_INT);
$stmt->bindValue(':num2', $num2, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetch(PDO::FETCH_ASSOC);

echo "加法运算结果：" . $result['sum'] . "<br>";

// 减法运算
$sql = "SELECT :num1 - :num2 AS difference";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(':num1', $num1, PDO::PARAM_INT);
$stmt->bindValue(':num2', $num2, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetch(PDO::FETCH_ASSOC);

echo "减法运算结果：" . $result['difference'] . "<br>";

// 乘法运算
$sql = "SELECT :num1 * :num2 AS product";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(':num1', $num1, PDO::PARAM_INT);
$stmt->bindValue(':num2', $num2, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetch(PDO::FETCH_ASSOC);

echo "乘法运算结果：" . $result['product'] . "<br>";

// 除法运算
$sql = "SELECT :num1 / :num2 AS quotient";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(':num1', $num1, PDO::PARAM_INT);
$stmt->bindValue(':num2', $num2, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetch(PDO::FETCH_ASSOC);

echo "除法运算结果：" . $result['quotient'] . "<br>";