我尝试在刷新时显示下一行，但我得到一个空白页面

Question

Hey I try to display next row on refresh and when it arrive at last row to take it from the beginning. Here is my table

col1 row(1)
col2 row(1)
col3 row(1)
col4 row(1)
col5 row(1)

and on refresh to get

col1 row(2)
col2 row(2)
col3 row(2)
col4 row(2)
col5 row(2)

and when it arrive at last row take it from the beginning.

col1 row(1)
col2 row(1)
col3 row(1)
col4 row(1)
col5 row(1)

Here is the code so far:

<?php
include 'connect.php';
session_start();

if(isset($_SESSION["id"])){
    $_SESSION["id"] = $_SESSION["id"] + 1;
}
else{
    $_SESSION["id"] = 1;
}

$id = $_SESSION["id"];

//Your mysql connection 

$results = mysqli_query($con, "SELECT * FROM testtable WHERE `id` = $id") or die('AM error occured: ' . mysqli_error());

while($row = mysqli_fetch_array($results)){
    echo $row["content0"];
    echo "<br>";
    echo $row["content1"];
      echo "<br>";
    echo $row["content2"];
      echo "<br>";
    echo $row["content3"];
      echo "<br>";
    echo $row["content4"];
      echo "<br>";
    echo $row["content5"];

}

Answer 1

<?php
include 'connect.php';
session_start();

if(isset($_SESSION["id"])){
    $_SESSION["id"] = $_SESSION["id"] + 1;
}
else{
    $_SESSION["id"] = 1;
}

$id = $_SESSION["id"];

//Your mysql connection 

$result=mysqli_query($con,"SELECT count(id) as total from testtable");
$data=mysqli_fetch_assoc($result);
echo $data['total'];
if($data['total']<$id )
{
$_SESSION["id"] = 1;
    $id=1;
} 


$results = mysqli_query($con, "SELECT * FROM testtable WHERE `id` = $id") or die('AM error occured: ' . mysqli_error());

while($row = mysqli_fetch_array($results)){
    echo $row["content0"];
    echo "<br>";
    echo $row["content1"];
      echo "<br>";
    echo $row["content2"];
      echo "<br>";
    echo $row["content3"];
      echo "<br>";
    echo $row["content4"];
      echo "<br>";
    echo $row["content5"];

}

explanation:

here we are getting total records and checking with current refreshed item, if greater then that we are assigning to start(1)