Question

我已经设置了一个数据库和一个小网站。在网站上，我应该能够看到数据库中的所有数据，并显示新条目。为此，我已经包含了＆＃34; setInterval（）;＆＃34;。 setinterval每秒都会启动应该读取数据库的函数。我没有得到任何错误，第一次该函数实际读取整个数据库，但它只是每秒写入相同的东西，没有任何来自数据库的新输入。每次我的函数被称为数据库中的所有内容（包括所有新条目）时，我怎么能做到这一点。

var t= "";
setInterval(checkDb, 1000);
function checkDb(){
    <?php
        session_start();
            $servername = "localhost";
            $username = "user";
            $password = "password";
            $dbname = "RFID";
            // Create connection
            $conn = new mysqli($servername, $username, $password, $dbname);
                // Check connection
                if ($conn->connect_error) {
                     die("Connection failed: " . $conn->connect_error);
                }
                $sql = 'SELECT `id`, `rfid`, `dateandtime` FROM`scans`';
                    $result = $conn->query($sql);

                    if ($result->num_rows > 0) {

                    // output data of each row
                    while($row = $result->fetch_assoc()) {
                        $answer= "id: " . $row["id"]. " - RFID: " . $row["rfid"]. " - Date:" . $row["dateandtime"]. "<br>";
                    ?>

                    t= <?php echo json_encode($answer);?> + t ;
                    document.getElementById("myP").innerHTML = t;
                    <?php
                    }
                    } else {
                       echo "<br>" ."\n0 results\n";
                    }
                    $conn->close();
            session_destroy();?>
            t="";
        };

Answer 1

您可以在第一次打开页面时使用jquery load加载php脚本，然后在x秒加载脚本后使用setInterval

<script type="text/javascript">
        $('document').ready(function(){
            $('#myP').load('php-script.php');//load the script immediately 
            setInterval(function(){setUpdates()}, 10000);

        });

        function setUpdates(){

            $('#myP').load('php-script.php');
        }

    </script>

<强> PHP-的script.php

<?php
session_start();
$servername = "localhost";
$username   = "user";
$password   = "password";
$dbname     = "RFID";
// Create connection
$conn       = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
$sql    = 'SELECT `id`, `rfid`, `dateandtime` FROM`scans`';
$result = $conn->query($sql);

if ($result->num_rows > 0) {

    // output data of each row
    while ($row = $result->fetch_assoc()) {
        $answer = "id: " . $row["id"] . " - RFID: " . $row["rfid"] . " - Date:" . $row["dateandtime"] . "<br>";
    }
} else {
    echo "<br>" . "\n0 results\n";
}
$conn->close();
session_destroy(); // I dont think u need this
?>

使用新的SQL查询每秒更新网站

1 个答案: