在 PHP MySQL 搜索中未找到结果时显示消息
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Displaying message when no results found in PHP MySQL search
提问by Callum Whyte
I have a PHP search script which queries a MySQL database. Currently, when no results are displayed the script shows and error. How can I make it display a message like "No Results were found" when nothing is returned?
我有一个查询 MySQL 数据库的 PHP 搜索脚本。目前，当没有显示任何结果时，脚本会显示并出错。当没有返回任何内容时，如何使其显示类似“未找到结果”的消息？
My PHP script is:
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);
}
?>
采纳答案by Sjoerd
if (empty($results)) {
echo 'No results found';
} else {
echo implode($results);
}
回答by Heart
Create a MYSQL Connection and paste this code below
创建一个 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($count>=1){if result was found}
else {if result was not found}
?>
回答by Tieson T.
You could count the number of elements in the array, and either continue with your implode or display the message you mentioned.
您可以计算数组中元素的数量，然后继续内爆或显示您提到的消息。
<?php
if(count($results) > 0){
echo implode($results);
}
else {
echo "No results were found.";
}
?>
You also really should not be using the mysql_* functions. Use either the improved version (mysqli_*) or PDO.
您也不应该使用 mysql_* 函数。使用改进版本 (mysqli_*) 或 PDO。
回答by Shef
<?php
mysql_connect("localhost","username","password");
mysql_select_db("database");
if(!empty($_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';
}
}
?>
回答by Marc Towler
Try the following:
请尝试以下操作：
<?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);
}
}
?>
Also please either use MySQLi or PDO as it is safer and better to use, some information can be found below. Personally I prefer MySQLi but prepared statements in PDO is really good and saves some lines of code every time you query ;)
另外请使用 MySQLi 或 PDO，因为它更安全，更好用，一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，每次查询时都可以节省一些代码行；)
回答by Chris9
How about a simple counter in the while statement:
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';}
回答by drfranks3
You could also use the function mysql_num_rows, which will tell you the number of rows returned by your query.
您还可以使用函数mysql_num_rows，它会告诉您查询返回的行数。
$rows = mysql_num_rows($searchResult);
if($rows <= 0){
/* Code if there are no rows */
}
else{
/* At least one row has been found */
}
回答by Scott C Wilson
if (mysql_num_rows($searchResult) == 0) {
echo "some error message";
} else {
... process data
}
