我已经用 PHP 为搜索页面编写了这段代码，我想知道一种使搜索结果更准确的方法。一些搜索字符串会提取数据库中的所有内容，因为它包含该词。这是我的代码
<?php include("header.php");?>
<h3>Rental Search Results</h3>
<div class="searchbox">
<form method="get" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label for="usersearch">Search Rentals Now:</label>
<input type="text" name="usersearch" value="<?php echo $_GET['usersearch']; ?>" />
<input type="submit" name="submit" value="Search" />
</form>
</div>
<br />
<br />
<?php
// This function builds a search query from the search keywords and sort setting
function build_query($user_search, $sort) {
$search_query = "SELECT * FROM online_rental_db";
// Extract the search keywords into an array
$clean_search = str_replace(',', ' ', $user_search);
$search_words = explode(' ', $clean_search);
$final_search_words = array();
if (count($search_words) > 0) {
foreach ($search_words as $word) {
if (!empty($word)) {
$final_search_words[] = $word;
}
}
}
// Generate a WHERE clause using all of the search keywords
$where_list = array();
if (count($final_search_words) > 0) {
foreach($final_search_words as $word) {
$where_list[] = "Description LIKE '%$word%' OR Manufacturer LIKE '%$word%' OR Model LIKE '%$word%' OR Category LIKE '%$word%'";
}
}
$where_clause = implode(' OR ', $where_list);
// Add the keyword WHERE clause to the search query
if (!empty($where_clause)) {
$search_query .= " WHERE $where_clause";
}
// Sort the search query using the sort setting
switch ($sort) {
// Ascending by job title
case 1:
$search_query .= " ORDER BY Description";
break;
// Descending by job title
case 2:
$search_query .= " ORDER BY Description DESC";
break;
// Ascending by state
case 3:
$search_query .= " ORDER BY Manufacturer";
break;
// Descending by state
case 4:
$search_query .= " ORDER BY Manufacturer DESC";
break;
// Ascending by date posted (oldest first)
case 5:
$search_query .= " ORDER BY Model";
break;
// Descending by date posted (newest first)
case 6:
$search_query .= " ORDER BY Model DESC";
break;
default:
// No sort setting provided, so don't sort the query
}
return $search_query;
}
// This function builds navigational page links based on the current page and the number of pages
function generate_page_links($user_search, $sort, $cur_page, $num_pages) {
$page_links = '';
// If this page is not the first page, generate the "previous" link
if ($cur_page > 1) {
$page_links .= '<a href="' . $_SERVER['PHP_SELF'] . '?usersearch=' . $user_search . '&sort=' . $sort . '&page=' . ($cur_page - 1) . '"><-</a> ';
}
else {
$page_links .= '<- ';
}
// Loop through the pages generating the page number links
for ($i = 1; $i <= $num_pages; $i++) {
if ($cur_page == $i) {
$page_links .= ' ' . $i;
}
else {
$page_links .= ' <a href="' . $_SERVER['PHP_SELF'] . '?usersearch=' . $user_search . '&sort=' . $sort . '&page=' . $i . '"> ' . $i . '</a>';
}
}
// If this page is not the last page, generate the "next" link
if ($cur_page < $num_pages) {
$page_links .= ' <a href="' . $_SERVER['PHP_SELF'] . '?usersearch=' . $user_search . '&sort=' . $sort . '&page=' . ($cur_page + 1) . '">-></a>';
}
else {
$page_links .= ' ->';
}
return $page_links;
}
// Grab the sort setting and search keywords from the URL using GET
$user_search = $_GET['usersearch'];
// Calculate pagination information
$cur_page = isset($_GET['page']) ? $_GET['page'] : 1;
$results_per_page = 5; // number of results per page
$skip = (($cur_page - 1) * $results_per_page);
// Start generating the table of results
echo '<table class="results">';
echo '<td align="center">Description</td><td align="center">Manufacturer</td><td align="center">Model #</td><td align="center">Image</td>';
// Generate the search result headings
echo '<tr class="bottomborder">';
echo '</tr>';
// Connect to the database
require_once('connectvars.php');
$dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
// Query to get the total results
$query = build_query($user_search,'');
$result = mysqli_query($dbc, $query);
$total = mysqli_num_rows($result);
$num_pages = ceil($total / $results_per_page);
// Query again to get just the subset of results
$query = $query . " LIMIT $skip, $results_per_page";
$result = mysqli_query($dbc, $query);
while ($row = mysqli_fetch_array($result)) {
$description = $row['Description'];
$model = $row['Model'];
$manufacturer = $row['Manufacturer'];
$image = $row['Image'];
$hour = $row['Hour'];
$day = $row['Day'];
$week = $row['Week'];
$month = $row['Month'];
$file = $row['PDF'];
$ID = $row['ID'];
$Category = $row['Category'];
$CTGID = $row['CTGID'];
if ($image == "") {
$image = "No Image";
}else {
$image = "<a class=\"thumbnail\" href=\"pp.php?ID=$ID\"><img class=\"rental_image\" src=\"$image\"><span><img src=\"$image\" ><br> $description</span></a>";
}
echo '<tr>';
echo "<td align=\"center\" valign=\"middle\" width=\"25%\"><a href=\"pp.php?ID=$ID\" alt=\"$description\">$description</a></td>";
echo "<td align=\"center\" valign=\"middle\" width=\"25%\"><a href=\"pp.php?ID=$ID\">$manufacturer</a></td>";
echo "<td align=\"center\" valign=\"middle\" width=\"25%\"><a href=\"pp.php?ID=$ID\">$model</a></td>";
echo "<td align=\"center\" valign=\"middle\" width=\"25%\">$image</td>";
echo '</tr>';
}
echo '</table>';
// Generate navigational page links if we have more than one page
if ($num_pages > 1) {
echo generate_page_links($user_search, '', $cur_page, $num_pages);
}
mysqli_close($dbc);
?>
<?php include("footer.php");?>
</div>
</body>
</html>