这不是重复的条目。我已经阅读了相同内容的上一篇文章，但我无法找到解决方案。这就是为什么我决定发布这个。
编辑02
<!-- language: lang-php -->
<?php
if (isset($_POST['lab_id']) && is_numeric($_POST['lab_id']))
{
$lab_id = $_POST['lab_id'];
}
else if (isset($_GET['lab_id']) && is_numeric($_GET['lab_id']))
{
$lab_id = $_GET['lab_id'];
}
//$targetpage = "view_all_chemicallab.php";
$limit = 2;
$query = "SELECT COUNT(*) as num FROM chemical
JOIN lab_inventory_chemical ON chemical.chemical_code = lab_inventory_chemical.chemical_code
WHERE lab_inventory_chemical.lab_id= '$lab_id' "; // this is line 71
$total_pages = mysql_fetch_array(mysql_query($query));
$total_pages = $total_pages['num'];
$stages = 3;
$page =isset($_GET['name'])?mysql_escape_string($_GET['page']): '';
if($page){
$start = ($page - 1) * $limit;
}else{
$start = 0;
}
// Get page data
$query1 = "SELECT * FROM chemical
JOIN lab_inventory_chemical ON chemical.chemical_code = lab_inventory_chemical.chemical_code
WHERE lab_inventory_chemical.lab_id='$lab_id' LIMIT $start, $limit"; //this is line 86
$result = mysql_query($query1);
// Initial page num setup
if ($page == 0){$page = 1;}
$prev = $page - 1;
$next = $page + 1;
$lastpage = ceil($total_pages/$limit);
$LastPagem1 = $lastpage - 1;
$paginate = '';
if($lastpage > 1)
{
// $paginate.= "<a href='$targetpage?page=$counter'>$counter</a>
$paginate .= "<div class='paginate'>";
// Previous
if ($page > 1){
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$prev'>previous</a>";
}else{
$paginate.= "<span class='disabled'>previous</span>"; }
// Pages
if ($lastpage < 7 + ($stages * 2)) // Not enough pages to breaking it up
{
for ($counter = 1; $counter <= $lastpage; $counter++)
{
if ($counter == $page){
$paginate.= "<span class='current'>$counter</span>";
}else{
$paginate.= "<a href='view_all_chemicallab.php?lab_id=1&page=$counter'>$counter</a>";}
// $paginate.= "<a href='$targetpage?page=$counter'>$counter</a>";}
}
}
elseif($lastpage > 5 + ($stages * 2)) // Enough pages to hide a few?
{
// Beginning only hide later pages
if($page < 1 + ($stages * 2))
{
for ($counter = 1; $counter < 4 + ($stages * 2); $counter++)
{
if ($counter == $page){
$paginate.= "<span class='current'>$counter</span>";
}else{
//$paginate.= "<a href='$targetpage?page=$counter'>$counter</a>";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$counter'>$counter</a>";}
}
$paginate.= "...";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$LastPagem1'>$LastPagem1</a>";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$lastpage'>$lastpage</a>";
}
// Middle hide some front and some back
elseif($lastpage - ($stages * 2) > $page && $page > ($stages * 2))
{
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=1'>1</a>";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=2'>2</a>";
$paginate.= "...";
for ($counter = $page - $stages; $counter <= $page + $stages; $counter++)
{
if ($counter == $page){
$paginate.= "<span class='current'>$counter</span>";
}else{
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$counter'>$counter</a>";}
}
$paginate.= "...";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$LastPagem1'>$LastPagem1</a>";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$lastpage'>$lastpage</a>";
}
// End only hide early pages
else
{
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=1'>1</a>";
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=2'>2</a>";
$paginate.= "...";
for ($counter = $lastpage - (2 + ($stages * 2)); $counter <= $lastpage; $counter++)
{
if ($counter == $page){
$paginate.= "<span class='current'>$counter</span>";
}else{
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$counter'>$counter</a>";}
}
}
}
// Next
if ($page < $counter - 1){
$paginate.= "<a href='view_all_chemicallab.php?lab_id=$lab_id&page=$next'>next</a>";
}else{
$paginate.= "<span class='disabled'>next</span>";
}
$paginate.= "</div>";
}
// get results from database
// $result = mysql_query("SELECT * FROM members")
// or die(mysql_error());
// display data in table
echo "<div>";
echo "<table id='table1'>";
echo "<tr> <th>Chemical Name</th> <th>Chemical Code</th> <th>Type</th> <th>Edit</th><th>Delete</th><th>Stock</th> </tr>";
// loop through results of database query, displaying them in the table
while($row = mysql_fetch_array( $result ))
{
// echo out the contents of each row into a table
echo "<tr>";
echo '<td>'. $row['name'] . '</td>';
echo '<td>' . $row['chemical_code'] . '</td>';
echo '<td>' . $row['type'] . '</td>';
echo '<td><a href="editchemical.php?chemical_code=' . $row['chemical_code'] . '">Edit</a></td>';
echo "<td><a href=\"delete_chemical.php?chemical_code=" . $row['chemical_code'] ."\" * onclick=\"return confirm('Are you sure you want to delete?')\">Delete</a></td>";
echo '<td><a href="stock_chemical.php?chemical_code=' . $row['chemical_code'] . '">Stock</a></td>';
echo "</tr>";
}
echo "</table>";
echo $paginate;
echo "</div>";
?>
我在php中遇到分页问题。我已经花了3天时间，但我找不到错误。所以最后决定向你们寻求帮助。这个分页脚本简单的查询，比如来自员工的Select *。但是当我在mysql查询中使用join时它会出错（第1页没有错误。但是当我点击分页页面时没有结果和错误）。
--- ---错误
1.Notice：未定义的变量：第71行的F：\ xampplite \ htdocs \ chem \ view_all_chemicallab.php中的lab_id
2.Notice：未定义的变量：第86行的F：\ xampplite \ htdocs \ chem \ view_all_chemicallab.php中的lab_id
（使用评论选项在上面的代码中显示错误行）
请帮帮我。提前致谢
答案 0 :(得分：0)
在脚本的顶部定义$ lab_id = null;希望它对你有用。
答案 1 :(得分：0)
您的$lab_id变量似乎是通过表单中的POST发送的。在您的分页链接中，您不会再次提及它。因此，当您单击该链接时，服务器不再知道查询是什么。您需要像其他变量（$targetPage和$counter一样将其再次传回页面，这样您的查询仍然可以写入 - 或者将其保留在会话或cookie中或其他什么。
此外，您的代码容易受到注入攻击。您确实应该更改代码以使用PDO或Mysqli。不应使用旧的mysql_query类型命令。
编辑：在标题处尝试：
if (isset($_POST['lab_id']) && is_numeric($_POST['lab_id']))
{
$lab_id = $_POST['lab_id'];
}
else
{
if(!isset($_GET['lab_id']))
{
$lab_id="";
// this means that the query will fail and you need to
// make sure that your script never gets to here
}
else
{
// Do any other checking/verification here
$lab_id=$_GET['lab_id'];
}
}
这将确保始终设置lab_id（尽管它可能仍为空，请参阅上面的代码）。但是在你的$targetpage变量中，有这样的东西：
$targetpage = "view_all_chemicallab.php?lab_id=".$lab_id;
编辑2：
您将不得不修改代码中的一些链接，以使href标记不包含两个？在$paginate.= "<a href='$targetpage?page=$counter'>$counter</a>之内，因为已经存在了？在变量$targetpage。
编辑3： 您目前的代码是：
$paginate.= "<a href='$targetpage?page=$counter'>$counter</a>"
问题在于$targetpage已在上面定义为：
$targetpage = "view_all_chemicallab.php?lab_id=".$lab_id;
这意味着当你将两者结合起来时，你最终会得到：
$paginate.= "<a href='view_all_chemicallab.php?lab_id=1?page=$counter'>$counter</a>"
// I used lab_id as 1 fot this example
这是一个无效的链接。传递多个参数的方法是使用&符号连接它们。这适用于paginate：
$paginate.= "<a href='$targetpage&page=$counter'>$counter</a>"
这将导致链接为：
<a href='view_all_chemicallab.php?lab_id=1&page=$counter'>$counter</a>
这是形成它的正确方法。