Question

<html>
<head>
    <title>PHP test</title>
    <link href="style.css" rel="stylesheet" type="text/css">
</head>
<body>


<div id="formDiv">  
    <form action="testphp.php" method="post">
        Email: <input type="text" name="email"><br>
        <textarea name="comment" rows="10" cols="40">Your comment here.</textarea>
        <input type="submit" value="submit">
    </form>

<div id="show">         
<?php


    $con=mysqli_connect("","root","","my_db");
    // Check connection
    if (mysqli_connect_errno())
    {
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }

    $result = mysqli_query($con,"SELECT * FROM Comments");

    echo "<table border='1'>
    <tr>
    <th>Email</th>
    <th>Comment</th>
    </tr>";

    while($row = mysqli_fetch_array($result))
    {
        echo "<tr>";
        echo "<td>" . $row['Email'] . "</td>";
        echo "<td>" . $row['comment'] . "</td>";
        echo "</tr>";
    }
    echo "</table>";

    mysqli_close($con);
?>
</div>
</div>

<?php

$con=mysqli_connect("","root","","my_db");

  if($_SERVER["REQUEST_METHOD"] == "POST")
  {

if(empty($_POST["comment"]))
    {echo "You have to write something. <br>"; 
     echo "<meta http-equiv=\"refresh\" content=\"2;URL=testphp.php\">";
}


else
    {
      if (mysqli_connect_errno())
        {
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
        }

        if(empty($_POST["email"]))
        {
        $sql="INSERT INTO Comments (Email, comment)
        VALUES
        ('$_POST[email]', '$_POST[comment]')";
        //echo "1 record added.";
        echo "<meta http-equiv=\"refresh\" content=\"2;URL=testphp.php\">";
            if (!mysqli_query($con,$sql))
                {
                    die('Error: ' . mysqli_error($con));
                }

        }
        else{
            if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$_POST["email"]))
            {
            echo "Invalid email format <br>";
            echo "<meta http-equiv=\"refresh\" content=\"2;URL=testphp.php\">"; 
            }
               else{
          $sql="INSERT INTO Comments (Email, comment)
          VALUES
          ('$_POST[email]', '$_POST[comment]')";
        echo "<meta http-equiv=\"refresh\" content=\"2;URL=testphp.php\">";

        if (!mysqli_query($con,$sql))
        {
            die('Error: ' . mysqli_error($con));
        }

           }
    }
    }
}

$db = mysql_selectdb('my_db', $con) or trigger_error("SQL", E_USER_ERROR);

    //number of rows in table
    $sql = "SELECT COUNT (*) FROM Comments";
    $result = mysql_query($sql, $con) or trigger_error("SQL", E_USER_ERROR);
    $r = mysql_fetch_row($result);
    $numRows = $r[0];

    //number of rows to show per page
    $rowsPerPage = 10;
    $totalPages = ceil($numRows/$rowsPerPage);

    //get current page or set default
    if(isset($_GET['currentpage']) && is_numeric($_GET['currentpage'])){
        $currentpage = (int) $_GET['currentpage'];
    }
    else{
        $currentpage = 1;
    }

    if($currentpage > $totalPages){
        $currentpage = $totalPages;
    }
    if($currentpage < 1){
        $currentpage = 1;
    }

    $offset = ($currentpage - 1) * $rowsPerPage;

    //get info from DB
    $sql = "SELECT comment FROM Comments LIMIT $offset, $rowsPerPage";
    $result = mysql_query($sql, $con) or trigger_error("SQL", E_USER_ERROR);

    while($list = mysql_fetch_assoc($result)){
        echo $list['comment'];
        echo "<br />";
    }

    //build pagination links
    if($currentpage > 1){
        echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=1'><<</a> ";
        $prevpage = $currentpage - 1;
        echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$prevpage'><</a> ";
    }

    $range = 3;

    for ($x = ($currentpage - $range); $x < (($currentpage + $range)  + 1); $x++) {
  // if it's a valid page number...
    if (($x > 0) && ($x <= $totalpages)) {
  // if we're on current page...
        if ($x == $currentpage) {
     // 'highlight' it but don't make a link
            echo " [<b>$x</b>] ";
  // if not current page...
        }
        else{
            echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$x'>$x</a> ";
        }
    }
    }

    if($currentpage != $totalpages){
        $nextpage = $currentpage + 1;
        echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$nextpage'>></a> ";
        echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$totalpages'>>></a> ";
    }
?>



</body>
</html>

这是我的代码，我从其他网站获取了分页代码，并尝试更改它以满足我的需求，但我无法使其工作。我收到了这行代码的警告

$db = mysql_selectdb('my_db', $con) or trigger_error("SQL", E_USER_ERROR);) 
Warning: mysql_selectdb() expects parameter 2 to be resource.

这是我第一次使用php进行编程，我已经尝试了分页的所有代码，但它只是不起作用...

分页不起作用

0 个答案: