Question

您的SQL语法有错误;检查与MySQL服务器版本对应的手册，以便在第1行的“-20,20”附近使用正确的语法

这是我收到的错误消息。当我搜索其中一个项目时它起作用，但是对于搜索的所有其他项目返回这个项目。我知道它与我的分页有关。

不确定它是否与系统中的记录有关，因为我还没有很多测试项目。我已经确保我不会搜索超过一半结果中出现的任何内容。我已经看了一段时间了，不知道为什么限制是错误的！

这是我的代码。

 $sql = mysql_query("SELECT * FROM users ORDER BY `$sortby` ASC")  or die(mysql_error());

///////////////////////////////////  Pagination Logic ////////////////////////////////////////////////////////////////////////
$nr = mysql_num_rows($sql); // Get total of Num rows from the database query
if (isset($_GET['pn'])) { // Get pn from URL vars if it is present
    $pn = preg_replace('#[^0-9]#i', '', $_GET['pn']); // filter everything but numbers for security(new)
    //$pn = ereg_replace("[^0-9]", "", $_GET['pn']); // filter everything but numbers for security(deprecated)
} else { // If the pn URL variable is not present force it to be value of page number 1
    $pn = 1;
} 
//This is where we set how many database items to show on each page 
$itemsPerPage = 20; 
// Get the value of the last page in the pagination result set
$lastPage = ceil($nr / $itemsPerPage);
// Be sure URL variable $pn(page number) is no lower than page 1 and no higher than $lastpage
if ($pn < 1) { // If it is less than 1
    $pn = 1; // force if to be 1
} else if ($pn > $lastPage) { // if it is greater than $lastpage
    $pn = $lastPage; // force it to be $lastpage's value
} 
// This creates the numbers to click in between the next and back buttons
// This section is explained well in the video that accompanies this script
$centerPages = "";
$sub1 = $pn - 1;
$sub2 = $pn - 2;
$add1 = $pn + 1;
$add2 = $pn + 2;
if ($pn == 1) {
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
} else if ($pn == $lastPage) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
} else if ($pn > 2 && $pn < ($lastPage - 1)) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub2 . '">' . $sub2 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add2 . '">' . $add2 . '</a> &nbsp;';
} else if ($pn > 1 && $pn < $lastPage) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
}
// This line sets the "LIMIT" range... the 2 values we place to choose a range of rows from database in our query
$limit = 'LIMIT '.($pn - 1) * $itemsPerPage .', ' .$itemsPerPage; 
// Now we are going to run the same query as above but this time add $limit onto the end of the SQL syntax
// $sql2 is what we will use to fuel our while loop statement below
$sql2  = mysql_query("SELECT * FROM users ORDER BY $sortby ASC $limit")  or die(mysql_error());
//////////////////////////////// END  Pagination Logic ////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////// Pagination Display Setup /////////////////////////////////////////////////////////////////////
$paginationDisplay = ""; // Initialize the pagination output variable
// This code runs only if the last page variable is ot equal to 1, if it is only 1 page we require no paginated links to display
if ($lastPage != "1"){
    // This shows the user what page they are on, and the total number of pages
    $paginationDisplay .= 'Page <strong>' . $pn . '</strong> of ' . $lastPage. '&nbsp;  &nbsp;  &nbsp; ';
    // If we are not on page 1 we can place the Back button
    if ($pn != 1) {
        $previous = $pn - 1;
        $paginationDisplay .=  '&nbsp;  <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $previous . '"> Back</a> ';
    } 
    // Lay in the clickable numbers display here between the Back and Next links
    $paginationDisplay .= '<span class="paginationNumbers">' . $centerPages . '</span>';
    // If we are not on the very last page we can place the Next button
    if ($pn != $lastPage) {
        $nextPage = $pn + 1;
        $paginationDisplay .=  '&nbsp;  <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $nextPage . '"> Next</a> ';
    } 
}
//////////////////////////////// END  Pagination Display Setup ////////////////////////////////////////////////////////////////////////////////

很抱歉，如果它有很大一部分代码：S任何帮助都会很棒。

Answer 1

// This line sets the "LIMIT" range... the 2 values we place to choose a range of rows from database in our query
$limit = 'LIMIT '.($pn - 1) * $itemsPerPage .', ' .$itemsPerPage;

这里似乎是你的问题...如果给你第0页会怎么样？那么它将是0-1 * 20 = -20,20

你不能有负偏移...你需要改变你的页码被正确解释的方式，比如如果检测到$ pn的0然后将其设置为1？

Answer 2

看起来你可能正在做LIMIT -20,20，这不是一个有效的范围。

$ itemsPerPage应该是有效范围的正数，例如1，

至少使用mysql_real_escape_string（）

清理数据输入

请在此处阅读。

http://php.net/manual/en/function.mysql-real-escape-string.php

MySQL分页限制

2 个答案: