mysqli的函数

// 面向过程方式
$conn = mysqli_connect("localhost", "username", "password", "database");

if (!$conn) {
    die("连接失败: " . mysqli_connect_error());
}

// 面向对象方式
$mysqli = new mysqli("localhost", "username", "password", "database");

if ($mysqli->connect_error) {
    die("连接失败: " . $mysqli->connect_error);
}

// 面向过程方式
$result = mysqli_query($conn, "SELECT * FROM table_name");

while ($row = mysqli_fetch_assoc($result)) {
    echo $row['column_name'];
}

// 面向对象方式
$result = $mysqli->query("SELECT * FROM table_name");

while ($row = $result->fetch_assoc()) {
    echo $row['column_name'];
}

// 面向对象方式
$stmt = $mysqli->prepare("SELECT * FROM table_name WHERE column_name = ?");
$stmt->bind_param("s", $value); // "s" 表示参数类型为字符串
$stmt->execute();
$result = $stmt->get_result();

while ($row = $result->fetch_assoc()) {
    echo $row['column_name'];
}
$stmt->close();