php 循环查询mysql

// 示例代码：使用预处理语句进行循环查询
$mysqli = new mysqli("localhost", "username", "password", "database");
if ($mysqli->connect_error) {
    die("连接失败: " . $mysqli->connect_error);
}

$stmt = $mysqli->prepare("SELECT id, name FROM users WHERE status = ?");
$status = 'active';
$stmt->bind_param("s", $status);

$stmt->execute();
$result = $stmt->get_result();

while ($row = $result->fetch_assoc()) {
    echo "ID: " . $row["id"] . " - Name: " . $row["name"] . "<br>";
}

$stmt->close();
$mysqli->close();

// 示例代码：分页循环查询
$page_size = 100;
$page_number = 1;

while (true) {
    $sql = "SELECT id, name FROM users LIMIT $page_size OFFSET " . ($page_number - 1) * $page_size;
    $result = $mysqli->query($sql);

    if ($result->num_rows > 0) {
        while ($row = $result->fetch_assoc()) {
            // 处理数据
        }
        $page_number++;
    } else {
        break;
    }
}

$mysqli->close();

// 示例代码：重新建立数据库连接
while (true) {
    $mysqli = new mysqli("localhost", "username", "password", "database");
    if ($mysqli->connect_error) {
        die("连接失败: " . $mysqli->connect_error);
    }

    // 执行查询操作

    $mysqli->close();
    sleep(1); // 适当休眠，避免频繁连接
}