我是PHP和MySQLI的新手，但是，我已经和他们讨论了几年。
我正在根据3个标准为我网站上的一些照片添加搜索功能。
我已经成功地在不同的页面上实现脚本，其中不包括页面限制的语法。但是，现在，当我添加我的$where_stmt代码时，我最终会遇到一些错误，而且我认为它与所需的放置有关}。
有问题的剧本是：
<?php
ini_set('display_errors',1);
error_reporting(E_ALL);
if (!defined('DB_SERVER')) define('DB_SERVER', 'xxx');
if (!defined('DB_USER')) define('DB_USER', 'xxx');
if (!defined('DB_PASSWORD')) define('DB_PASSWORD', 'xxx');
if (!defined('DB_TABLE')) define('DB_TABLE', 'xxx');
// The procedural way
$mysqli = mysqli_connect(DB_SERVER, DB_USER, DB_PASSWORD, DB_TABLE);
$mysqli->set_charset("utf8");
$mysqli->query("SET NAMES 'utf8'");
if (mysqli_connect_errno($mysqli)) {
trigger_error('Database connection failed: ' . mysqli_connect_error(), E_USER_ERROR);
}
// This first query is just to get the total count of rows
$sql = "SELECT COUNT(*) FROM tbl_photos";
$query = mysqli_query($mysqli, $sql);
$row = mysqli_fetch_row($query);
// Here we have the total row count
$rows = $row[0];
// This is the number of results we want displayed per page
$page_rows = 16;
// This tells us the page number of our last page
$last = ceil($rows/$page_rows);
// This makes sure $last cannot be less than 1
if($last < 1){
$last = 1;
}
// Establish the $pagenum variable
$pagenum = 1;
// Get pagenum from URL vars if it is present, else it is = 1
if(isset($_GET['pn'])){
$pagenum = preg_replace('#[^0-9]#', '', $_GET['pn']);
}
// This makes sure the page number isn't below 1, or more than our $last page
if ($pagenum < 1) {
$pagenum = 1;
} else if ($pagenum > $last) {
$pagenum = $last;
}
// This sets the range of rows to query for the chosen $pagenum
$limit = 'LIMIT ' .($pagenum - 1) * $page_rows .',' .$page_rows;
if(isset($_POST['submit']))
if(isset($_GET['go']))
if(isset($_REQUEST['submited'])) {
$tid = $_POST['tID'];
$lvmid = $_POST['lvmID'];
$lid = $_POST['lID'];
$where_stmt="";
// query only for LuchtvaartmaatschappijID (LVMID)
if((isset($lvmid) && !empty($lvmid)) && (!isset($tid) || empty($tid)) && (!isset($lid) || empty($lid)))
{
$where_stmt="WHERE lvm.luchtvaartmaatschappijID='".$lvmid."'";
}
// query only for ToestelID
elseif((isset($tid) && !empty($tid)) && (!isset($lvmid) || empty($lvmid)) && (!isset($lid) || empty($lid)))
{
$where_stmt="WHERE t.toestelID = '".$tid."'";
}
// query only for luchthaven
elseif((isset($lid) && !empty($lid)) && (!isset($lvmid) || empty($lvmid)) && (!isset($tid) || empty($tid)))
{
$where_stmt="WHERE img_location = '".$lid."'";
}
// query only for Luchtvaartmaatschappij and Toestel
elseif((isset($lvmid) && !empty($lvmid)) && (isset($tid) || !empty($tid)) && (!isset($lid) || empty($lid)))
{
$where_stmt="WHERE lvm.luchtvaartmaatschappijID='".$lvmid."' and t.toestelID='".$tid."'";
}
// query only for Luchtvaartmaatschappij and luchthaven
elseif((isset($lvmid) && !empty($lvmid)) && (isset($lid) || !empty($lid)) && (!isset($tid) || empty($tid)))
{
$where_stmt="WHERE lvm.luchtvaartmaatschappijID='".$lvmid."' and img_location = '".$lid."'";
}
// query for luchtvaartmaatschappij, toestel and luchthaven
elseif((isset($lvmid) && !empty($lvmid)) && (isset($tid) && !empty($tid)) && (isset($lid) && !empty($lid)))
{
$where_stmt="WHERE lvm.luchtvaartmaatschappijID='".$lvmid."' and t.toestelID='".$tid."' and img_location = '".$lid."'";
}
else
{
//where statement should be excluded as no filters are available
}
// This is your query again, it is for grabbing just one page worth of rows by applying $limit
$sql = "
SELECT randimgID, img_location, img_lvm, img_file, img_nmr, img_t, t.toestel, l.luchthavennaam, lvm.luchtvaartmaatschappij, lvm.luchtvaartmaatschappijID, t.toestelID
FROM tbl_photos p
LEFT JOIN tbl_luchthaven l
ON p.img_location = l.luchthavenID
LEFT JOIN tbl_luchtvaartmaatschappij lvm
ON p.img_lvm = lvm.IATAcode
LEFT JOIN tbl_toestel t
ON p.img_t = t.toestelID
$where_stmt
ORDER BY lvm.luchtvaartmaatschappij, t.toestel ASC, p.img_nmr ASC $limit";
$query = mysqli_query($mysqli, $sql);
/* determine number of rows result set */
$row_cnt = mysqli_num_rows($query);
// This shows the user what page they are on, and the total number of pages
$textline1 = "beelden (<b>$rows</b>)";
$textline2 = "Page <b>$pagenum</b> of <b>$last</b>";
// Establish the $paginationCtrls variable
$paginationCtrls = '';
// If there is more than 1 page worth of results
if($last != 1){
/* First we check if we are on page one. If we are then we don't need a link to
the previous page or the first page so we do nothing. If we aren't then we
generate links to the first page, and to the previous page. */
if ($pagenum > 1) {
$previous = $pagenum - 1;
$paginationCtrls .= '<li class="page-item"><a class="page-link" href="'.$_SERVER['PHP_SELF'].'?pn='.$previous.'">vorige</a> </li>';
// Render clickable number links that should appear on the left of the target page number
for($i = $pagenum-4; $i < $pagenum; $i++){
if($i > 0){
$paginationCtrls .= '<li class="page-item"><a class="page-link" href="'.$_SERVER['PHP_SELF'].'?pn='.$i.'">'.$i.'</a> </li>';
}
}
}
// Render the target page number, but without it being a link
$paginationCtrls .= '<li class="page-item active">
<a class="page-link" href="#">'.$pagenum.' <span class="sr-only">(current)</span></a>
</li>';
// Render clickable number links that should appear on the right of the target page number
for($i = $pagenum+1; $i <= $last; $i++){
$paginationCtrls .= '<li class="page-item"><a class="page-link" href="'.$_SERVER['PHP_SELF'].'?pn='.$i.'">'.$i.'</a> </li> ';
if($i >= $pagenum+4){
break;
}
}
// This does the same as above, only checking if we are on the last page, and then generating the "Next"
if ($pagenum != $last) {
$next = $pagenum + 1;
$paginationCtrls .= '<li class="page-item"><a class="page-link" href="'.$_SERVER['PHP_SELF'].'?pn='.$next.'">volgende</a> </li>';
}
}
$list = '';
$items_in_row = 2 ;
$index = 0 ;
echo "<table width='100%' cellspacing='1' border='0'>
<tr>";
while($row = mysqli_fetch_assoc($query)) {
$img_location = $row['luchthavennaam'];
$img_lvm = $row['img_lvm'];
$l = htmlspecialchars($row['luchtvaartmaatschappij']);
$lvmID = $row['luchtvaartmaatschappijID'];
$img_nmr = $row['img_nmr'];
$t = $row['toestel'];
$tid = $row['toestelID'];
$f = $row['img_file'];
$rID = $row['randimgID'];
$img_file = $row['img_file'];
$image = "http://globe-trekking.com/vg/img/gallery/$img_lvm/$img_file";
$link = "http://globe-trekking.com/vg/gallery/details.php?pid=$rID&lvmID=$lvmID&in=$img_nmr";
$index++ ;
echo "<td width='370' align='left' valign='top' bgcolor='#292960'> ";
echo "<table width='540' border='0' cellpadding='0' cellspacing='0'>";
echo "<tbody>";
echo " <tr>";
echo " <td height='15' colspan='3' bgcolor='#292960'></td>";
echo " </tr>";
echo " <tr>";
echo " <td height='15' colspan='3' bgcolor='#000033'></td>";
echo " </tr>";
echo "<tr>";
echo " <td width='15' bgcolor='#000033'> </td>";
echo " <td bgcolor='#000033'><a href='" . $link ."'><img src='".$image."' width='510'></a></td>";
echo " <td width='15' bgcolor='#000033'></td>";
echo "</tr>";
echo "<tr>";
echo " <td bgcolor='#000033'> </td>";
echo " <td bgcolor='#000033'><table width='510' border='0' align='center' cellpadding='0' cellspacing='0'>";
echo " <tr>";
echo " <td height='15' colspan='2' valign='top' style='text-align: left'> </td>";
echo " </tr>";
echo " <tr>";
echo " <td width='72%' valign='top' style='text-align: left'><span style='font-size: 18px; color: #DEDEDE'><a class='airline' href='gallery_lvm.php?lvmid=$lvmID'>" . $l . "</a></span></td>";
echo " <td width='28%' style='text-align: left'><span style='font-size: 14.5px; color: #DEDEDE'>Reg: <a class='airline' href='gallery_reg.php?reg=$img_nmr'>" . $img_nmr . "</a></span></td>";
echo " </tr>";
echo " <tr>";
echo " <td height='10' colspan='2' valign='top' style='text-align: left'></td>";
echo " </tr>";
echo " <tr>";
echo " <td valign='top' style='text-align: left'><span style='font-size: 14.5px; color: #DEDEDE'><a class='airline' href='gallery_t.php?tid=$tid'>" . $t . "</a></span></td>";
echo " <td style='text-align: left'> </td>";
echo " </tr>";
echo " <tr>";
echo " <td height='10' colspan='2' valign='top' style='text-align: left'></td>";
echo " </tr>";
echo " <tr>";
echo " <td colspan='2' valign='top' style='text-align: left'><span style='font-size: 14.5px; color: #DEDEDE'>" . $img_location . "</span><br>
<br>
</td>";
echo " </tr>";
echo " <tr>";
echo " <td style='text-align: left'> </td>";
echo " <td style='text-align: left'> </td>";
echo " </tr>";
echo " </table></td>";
echo " <td bgcolor='#000033'> </td>";
echo "</tr>";
echo "<tr>";
echo " <td> </td>";
echo " <td> </td>";
echo " <td> </td>";
echo "</tr>";
echo " </tbody>";
echo " </table>";
echo " </td>";
if ($index%$items_in_row == 0){
echo " </tr>";
echo " <tr>";
}
}
echo " </tr>";
echo " </table>";
// Close your database connection
mysqli_close($mysqli);
?>
<br />
<nav aria-label="Page Navigation">
<ul class="pagination justify-content-center">
<div class="pagination"><?php echo $paginationCtrls; ?></div>
</ul>
</nav>
<br />
</div>
<br />
<br />
</div>
<?php include '../includes/menu/footer.php'; ?>
</body>
</html>
当我在最后一个else语句之后添加它时，我最终得到一个错误，表明注意：未定义的变量：第174行的/xxx/xxx/public_html/vg/gallery/search_post.php中的where_stmt
// query for luchtvaartmaatschappij, toestel and luchthaven
elseif((isset($lvmid) && !empty($lvmid)) && (isset($tid) && !empty($tid)) && (isset($lid) && !empty($lid)))
{
$where_stmt="WHERE lvm.luchtvaartmaatschappijID='".$lvmid."' and t.toestelID='".$tid."' and img_location = '".$lid."'";
}
else
{
//where statement should be excluded as no filters are available
}
}
如果我在mysqli_close()之前添加它，那么它会抛出一个错误：
PHP注意：未定义的变量：第325行的/xxx/xxx/public_html/vg/gallery/search_post.php中的paginationCtrls
如果我把它全部放在一起，我在托管公司为我提供的网页编辑器中收到以下红色x错误：
意外的语法，错误$ E0F
在这一点上，我不确定应该放在哪里。
我应该注意，当我摆脱$where_stmt和$sql查询上方的代码时，我可以让代码工作。
我建议你看看像http://propelorm.org/documentation/reference/model-criteria.html#finding-objects这样的ORM库，以避免手写SQL和连接where子句。
还要确保在使用之前声明了$ paginationCtrls。