目前，当我在搜索引擎中输入“M”时，尽管我的数据库中存在“数学”值，但我没有得到任何结果。 （我在我的网站上使用Match Against mysql的功能）。所以我决定制作一个首先运行Match Against函数的代码，如果没有获得输出，它再次运行搜索，但这次使用我的sql的'LIKE'函数，如果仍然没有得到结果，则显示alert'没有值发现”。 代码的要点有点像这样..
mysql(Match against function)
If (mysqli_num_rows > 0)
{output}
elseif (mysqli_num_rows < 1)
{ mysqli (LIKE function)
then show output}
else {show alert'no results'}
当我在搜索引擎中输入“M”时，此代码是否会给出结果'Math'。
实际代码。
<?php
if (isset($_POST['go']))
{ $search = $_POST['search'];
$college = $_POST['colleges'];
if (!empty($search))
{
if(isset($_POST['colleges']) )
{
$query1 = "Select filename, description, groupid, emailid, college, upload_date FROM images WHERE MATCH(description) AGAINST('$search') AND college = '$college' group by groupid order by MATCH(description) AGAINST('$search') DESC";
$query_run1 = mysqli_query($con, $query1) ;
}
else
{
$query1 = "Select filename, description, groupid, emailid, college,upload_date FROM images WHERE MATCH(description) AGAINST('$search') group by groupid order by MATCH(description) AGAINST('$search') DESC";
$query_run1 = mysqli_query($con, $query1) ;
$searchresults = mysqli_num_rows($query_run1);
?><p class = "totalresults"> <br />
<br />     <font size= "4" >Total Results :
<?php
echo $searchresults ;
?>
</font> </p>
<?php
if(mysqli_num_rows($query_run1)>0)
{
?>
<table class="searchenginelist" style="color: black;">
<tr>
<th> Uploader </th>
<th> Title </th>
<th> Date </th>
<th> Upvotes </th>
<th> Downvotes </th>
<th> College </th>
</tr>
<?php
while( $rows = mysqli_fetch_assoc($query_run1))
{
//$imagedisplay = $rows['file'];
$imagename = $rows['filename'];
// mysqli_real_escape_string($con,$imagedisplay);
$descrip = $rows['description'];
$groupid = $rows['groupid'];
//$groupid = $_SESSION['groupid'] ;
$uploader_emailid = $rows['emailid'];
$college = $rows['college'];
?>
<tr>
<td width="70px"> <?php
$query = " SELECT username from userinfo WHERE emailid = '$uploader_emailid' " ;
$query_run = mysqli_query($con,$query );
$raw = mysqli_fetch_assoc($query_run);
echo $raw['username']; ?>
</td>
<td width="450px"> <a href="imagespace.php?groupid=<?php echo $groupid ;?>">
<?php echo $descrip ; ?>
</a>
</td>
<td style="font-size:15px;" width="85px">
<?php echo $rows['upload_date'] ; ?>
</td>
<td align="center" style="color:green;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '1' ";
$query_run= mysqli_query($con, $query);
$upvote=mysqli_num_rows($query_run) ;
echo $upvote;
?>
</td>
<td align="center" style="color:red;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '0' ";
$query_run= mysqli_query($con, $query);
$downvote=mysqli_num_rows($query_run) ;
echo $downvote;
?>
</td>
<td style="font-size:13px;" width="130px">
<?php echo $college; ?>
</td>
</tr>
<?php
}
?>
</table>
<?php
}
elseif(mysqli_num_rows($query_run1) < 1)
{
$query12 = "Select * FROM images WHERE description LIKE '%".mysqli_real_escape_string($con,$search)."%' group by groupid order by groupid DESC";
$query_run12 = mysqli_query($con, $query12) ;
?> <table class="searchenginelist" style="color: black;">
<tr>
<th> Uploader </th>
<th> Title </th>
<th> Date </th>
<th> Upvotes </th>
<th> Downvotes </th>
<th> College </th>
</tr>
<?php
while( $rows = mysqli_fetch_assoc($query_run12))
{
//$imagedisplay = $rows['file'];
$imagename = $rows['filename'];
// mysqli_real_escape_string($con,$imagedisplay);
$descrip = $rows['description'];
$groupid = $rows['groupid'];
//$groupid = $_SESSION['groupid'] ;
$uploader_emailid = $rows['emailid'];
$college = $rows['college'];
?>
<tr>
<td width="70px"> <?php
$query = " SELECT username from userinfo WHERE emailid = '$uploader_emailid' " ;
$query_run = mysqli_query($con,$query );
$raw = mysqli_fetch_assoc($query_run);
echo $raw['username']; ?>
</td>
<td width="450px"> <a href="imagespace.php?groupid=<?php echo $groupid ;?>">
<?php echo $descrip ; ?>
</a>
</td>
<td style="font-size:15px;" width="85px">
<?php echo $rows['upload_date'] ; ?>
</td>
<td align="center" style="color:green;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '1' ";
$query_run= mysqli_query($con, $query);
$upvote=mysqli_num_rows($query_run) ;
echo $upvote;
?>
</td>
<td align="center" style="color:red;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '0' ";
$query_run= mysqli_query($con, $query);
$downvote=mysqli_num_rows($query_run) ;
echo $downvote;
?>
</td>
<td style="font-size:13px;" width="130px">
<?php echo $college; ?>
</td>
</tr>
}
?>
</table>
<?php
}
else
{
echo '<script type="text/javascript"> alert ("No results found") </script>' ;
}
}
else
{ echo '<script type="text/javascript"> alert ("No data entered") </script>';
}
}
}
答案 0 :(得分：1)
您的代码中存在一些语法问题，您的其他语句未正确排列，因此您的页面无效。 （例如，您有一个} else {与另一个} else {对齐。
我浏览了所有代码并对其进行了格式化，以便我可以看到问题是什么，记住，一些合理的代码缩进将是一个好主意。 它可以帮助我们阅读代码，更重要的是它可以帮助调试代码。 Take a quick look at a coding standard为了您自己的利益。 您可能会被要求在几周/几个月内修改此代码，最后您会感谢我。
<?php
if (isset($_POST['go'])) {
$search = $_POST['search'];
$college = $_POST['colleges'];
if (!empty($search)) {
if(isset($_POST['colleges']) ) {
$query1 = "Select filename, description, groupid, emailid, college, upload_date FROM images WHERE MATCH(description) AGAINST('$search') AND college = '$college' group by groupid order by MATCH(description) AGAINST('$search') DESC";
$query_run1 = mysqli_query($con, $query1);
} else {
$query1 = "Select filename, description, groupid, emailid, college,upload_date FROM images WHERE MATCH(description) AGAINST('$search') group by groupid order by MATCH(description) AGAINST('$search') DESC";
$query_run1 = mysqli_query($con, $query1);
$searchresults = mysqli_num_rows($query_run1);
?>
<p class = "totalresults">
<br />
<br />
    <font size= "4" >Total Results: <?php echo $searchresults; ?></font>
</p>
<?php
if(mysqli_num_rows($query_run1)>0) {
?>
<table class="searchenginelist" style="color: black;">
<tr>
<th> Uploader </th>
<th> Title </th>
<th> Date </th>
<th> Upvotes </th>
<th> Downvotes </th>
<th> College </th>
</tr>
<?php
while( $rows = mysqli_fetch_assoc($query_run1)) {
//$imagedisplay = $rows['file'];
$imagename = $rows['filename'];
// mysqli_real_escape_string($con,$imagedisplay);
$descrip = $rows['description'];
$groupid = $rows['groupid'];
//$groupid = $_SESSION['groupid'] ;
$uploader_emailid = $rows['emailid'];
$college = $rows['college'];
?>
<tr>
<td width="70px">
<?php
$query = " SELECT username from userinfo WHERE emailid = '$uploader_emailid' " ;
$query_run = mysqli_query($con,$query );
$raw = mysqli_fetch_assoc($query_run);
echo $raw['username'];
?>
</td>
<td width="450px">
<a href="imagespace.php?groupid=<?php echo $groupid ;?>">
<?php
echo $descrip;
?>
</a>
</td>
<td style="font-size:15px;" width="85px">
<?php
echo $rows['upload_date'] ;
?>
</td>
<td align="center" style="color:green;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '1' ";
$query_run= mysqli_query($con, $query);
$upvote=mysqli_num_rows($query_run) ;
echo $upvote;
?>
</td>
<td align="center" style="color:red;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '0' ";
$query_run= mysqli_query($con, $query);
$downvote=mysqli_num_rows($query_run) ;
echo $downvote;
?>
</td>
<td style="font-size:13px;" width="130px">
<?php
echo $college;
?>
</td>
</tr>
<?php
} //end while loop
?>
</table>
<?php
} else if(mysqli_num_rows($query_run1) < 1) {
$query12 = "Select * FROM images WHERE description LIKE '%".mysqli_real_escape_string($con,$search)."%' group by groupid order by groupid DESC";
$query_run12 = mysqli_query($con, $query12) ;
?>
<table class="searchenginelist" style="color: black;">
<tr>
<th> Uploader </th>
<th> Title </th>
<th> Date </th>
<th> Upvotes </th>
<th> Downvotes </th>
<th> College </th>
</tr>
<?php
while( $rows = mysqli_fetch_assoc($query_run12)) {
//$imagedisplay = $rows['file'];
$imagename = $rows['filename'];
// mysqli_real_escape_string($con,$imagedisplay);
$descrip = $rows['description'];
$groupid = $rows['groupid'];
//$groupid = $_SESSION['groupid'] ;
$uploader_emailid = $rows['emailid'];
$college = $rows['college'];
?>
<tr>
<td width="70px">
<?php
$query = " SELECT username from userinfo WHERE emailid = '$uploader_emailid' " ;
$query_run = mysqli_query($con,$query );
$raw = mysqli_fetch_assoc($query_run);
echo $raw['username'];
?>
</td>
<td width="450px">
<a href="imagespace.php?groupid=<?php echo $groupid ;?>">
<?php
echo $descrip ;
?>
</a>
</td>
<td style="font-size:15px;" width="85px">
<?php
echo $rows['upload_date'] ;
?>
</td>
<td align="center" style="color:green;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '1' ";
$query_run= mysqli_query($con, $query);
$upvote=mysqli_num_rows($query_run) ;
echo $upvote;
?>
</td>
<td align="center" style="color:red;" width="50px">
<?php
$query = "SELECT vote from votes where groupid = '$groupid' and vote = '0' ";
$query_run= mysqli_query($con, $query);
$downvote=mysqli_num_rows($query_run) ;
echo $downvote;
?>
</td>
<td style="font-size:13px;" width="130px">
<?php
echo $college;
?>
</td>
</tr>
</table>
<?php
} //end while loop
} else { //num rows < 1
echo '<script type="text/javascript"> alert ("No results found") </script>' ;
}
}
} else { //no searches returned
echo '<script type="text/javascript"> alert ("No data entered") </script>';
}
}
我还建议，对于非常复杂的嵌套结构，要注释每个结束括号的内容，就像我在代码中所做的那样。我发表评论，以便能够确切地看到}结束的内容。
警告： This code may be vulnerable to SQL Injection Attacks 。您应该了解Prepared Statements或MySQLi的PDO。我推荐
PDO，我wrote a function for使其非常简单，非常干净，以及更强安全使用非参数化查询。
答案 1 :(得分：0)
如果您可以访问主机的mysql.ini，则只需更改全文搜索的最小字长即可。
[mysqld]
ft_min_word_len=N
否则，您应该决定要使用哪个搜索功能。如果一个搜索是全文搜索而另一个搜索是简单的LIKE，则用户不是很直观。
如果用户输入的字符数超过2个，则单向处理也可能只使用全文。
// ...
if (strlen($query) < 4) {
$where = "MATCH (...) AGAINST ...";
} else {
$where = "...LIKE ... ";
}
$sql .= $where;
顺便说一下。 MATCH AGAINST应该正常返回比结果更多的结果，所以在MATCH AGAINST返回0行后进行LIKE搜索是有点无用的。