Question

我有一个查询MySQL数据库的PHP搜索脚本。目前，当没有显示结果时，脚本显示和错误。如果没有返回任何内容，我怎样才能显示“未找到结果”这样的消息？

我的PHP脚本是：

<?php

mysql_connect("localhost","username","password");
mysql_select_db("database");

if(!empty($_GET['q'])){
$query=mysql_real_escape_string(trim($_GET['q']));
$searchSQL="SELECT * FROM links WHERE `title` LIKE '%{$query}%'  LIMIT 8";
$searchResult=mysql_query($searchSQL);

while ($row=mysql_fetch_assoc($searchResult)){
    $results[]="<div class='webresult'><div class='title'><a href='{$row['url']}'>{$row['title']}</a></div><div class='desc'>{$row['description']}</div><div class='url'>{$row['url']}</div></div>";
}

echo implode($results);
}

?>

Answer 1

if (empty($results)) { 
    echo 'No results found'; 
} else {
    echo implode($results);
}

Answer 2

创建MYSQL连接并将此代码粘贴到

下面

$sql="SELECT * FROM tablename WHERE columnname LIKE your variable or constant ";
$result=mysql_query($sql);

$count=mysql_num_rows($result);

if($count>=1){if result was found}

else {if result was not found}

?>

Answer 3

您可以计算数组中元素的数量，并继续进行内爆或显示您提到的消息。

<?php
     if(count($results) > 0){
         echo implode($results);
     }
     else {
         echo "No results were found.";
     }
?>

你也真的不应该使用mysql_ *函数。使用改进版本（mysqli_ *）或PDO。

Answer 4

尝试以下方法：

<?php

mysql_connect("localhost","username","password");
mysql_select_db("database");

if(!empty($_GET['q'])){
$query=mysql_real_escape_string(trim($_GET['q']));
$searchSQL="SELECT * FROM links WHERE `title` LIKE '%{$query}%'  LIMIT 8";
$searchResult=mysql_query($searchSQL);

if(mysql_num_rows($searchResult) <= 0)
{
    echo "No results";
} else {

    while ($row=mysql_fetch_assoc($searchResult)){
        $results[]="<div class='webresult'><div class='title'><a href='{$row['url']}'>{$row['title']}</a></div><div class='desc'>{$row['description']}</div><div class='url'>{$row['url']}</div></div>";
    }

    echo implode($results);
} 
}

?>

另外请使用MySQLi或PDO，因为它更安全，更好用，有些信息可以在下面找到。我个人更喜欢MySQLi，但PDO中的预处理语句非常好，每次查询时都会保存一些代码行;）

MySQLi and PHP

PDO and PHP

Answer 5

<?php

mysql_connect("localhost","username","password");
mysql_select_db("database");

if(!empty($_GET['q'])){
    $query          =   mysql_real_escape_string(trim($_GET['q']));
    $searchSQL      =   "SELECT * FROM links WHERE `title` LIKE '%{$query}%'  LIMIT 8";
    $searchResult   =   mysql_query($searchSQL);

    // the query was run successfully 
    // and it returned at least a result
    if(is_resource($searchResult) && mysql_num_rows($result) > 0){
        while ($row=mysql_fetch_assoc($searchResult)){
            $results[]="<div class='webresult'><div class='title'><a href='{$row['url']}'>{$row['title']}</a></div><div class='desc'>{$row['description']}</div><div class='url'>{$row['url']}</div></div>";
        }

        echo implode($results);
    } else{
        echo 'No Results were found';
    }
}
?>

Answer 6

您还可以使用函数mysql_num_rows，它将告诉您查询返回的行数。

$rows = mysql_num_rows($searchResult);
if($rows <= 0){
    /* Code if there are no rows */
}
else{
    /* At least one row has been found */
}

Answer 7

if (mysql_num_rows($searchResult) == 0) {
   echo "some error message"; 
} else { 
  ... process data
}

Answer 8

while语句中的简单计数器怎么样：

$i = 0;

while (condition) {
   $i++;
   do stuff;
}

if ($i ==0) {echo 'No results found';}

在PHP MySQL搜索中找不到结果时显示消息

8 个答案: