每秒鐘更新網站新的sql查詢

Question

我已經建立了一個數據庫和一個小網站。在網站上，我應該能夠看到數據庫中的所有數據並顯示新條目。爲此我包含了「setInterval（）;」。 setinterval每秒鐘啓動一個應該讀取數據庫的函數。我沒有收到任何錯誤，並且第一次函數實際讀取整個數據庫，但是它每秒都會寫入相同的內容，而沒有任何來自數據庫的新輸入。我怎樣才能讓每次我的函數被調用時，它也包含數據庫中的所有內容，包括所有neww條目。

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

你可以只加載使用jQuery負荷PHP腳本當你第一次打開網頁，然後在X秒加載使用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> 

PHP-script.php的

<?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 
?> 

腳本