10分钟后删除所有记录

Question

Edit: Fixed

I'm writing a user counter with mysql and php, this will update all connected users in 10 mins into a table, and every 10 mins, it will delete all records from that table.

My table is like:

id (int, auto increment) | session (varchar) | time (int)

But my query used to delete record is not correct, It doesnt work. Someone help me, plz!!!

<?php
 $session = session_id();
 $time = time();     
 $time_check = $time - 900;                
 $servername = "localhost";
 $username = "root";
 $password = "";
 $dbname = "user"; 
 $tbl_name = "useronline";   

// Create connection
 $conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
 if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
} 

// Update session
$sql = "SELECT * FROM $tbl_name WHERE session='$session'";
$result = $conn->query($sql);                   
$count = $result->num_rows;    
if ($count == "0") {
  $sql1 = "INSERT INTO $tbl_name(session, time)VALUES('$session', '$time')";
  $result1 = $conn->query($sql1);
} else {
  $sql2 = "UPDATE $tbl_name SET time='$time' WHERE session = '$session'";
  $result2 = $conn->query($sql2);
}

// Count session online
$sql3 = "SELECT * FROM $tbl_name";
$result3 = $conn->query($sql3);
$count_user_online = $result3->num_rows;

// Delete session
$sql4 = 'DELETE FROM useronline WHERE time<$time_check';
$result4 = $conn->query($sql4);

// Total session 
 $sql5 = 'SELECT id FROM useronline ORDER BY id DESC LIMIT 1';
 $result5 = $conn->query($sql5);
 $row = $result5->fetch_assoc();     
 $total = $row['id'];

 mysqli_close($conn);
 ?>

output:

User online: <?php echo $count_user_online; ?><br />
Total  :  <?php echo $total; ?> 

Answer 1

I dont understand you delete query, why are you doing a Not in ? Should'nt it be juste like this : 'DELETE FROM useronline WHERE time<$time_check'; ?