entityMap|blocks|key|3ujuu|text|而不是通过|type|unstyled|depth|inlineStyleRanges|entityRanges|data|dct1a|在至|3fe73|您实际上希望传递DB链接(由返回|1b4f3|)，它将为您提供受前一个查询影响的行数。请参见：|207um|http://uk.php.net/mysqli|98ju9|_|fq1h3|受影响|28fr4|5qbgf|行^0|0|0|0|0|0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|R|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|S|9|@]|A|@]|B|$]]|$2|E|4|F|6|7|8|T|9|@]|A|@]|B|$]]|$2|G|4|H|6|7|8|U|9|@]|A|@]|B|$]]|$2|I|4|J|6|7|8|V|9|@]|A|@]|B|$]]|$2|K|4|L|6|7|8|W|9|@]|A|@]|B|$]]|$2|M|4|N|6|7|8|X|9|@]|A|@]|B|$]]|$2|O|4|L|6|7|8|Y|9|@]|A|@]|B|$]]|$2|P|4|Q|6|7|8|Z|9|@]|A|@]|B|$]]]]

Rather than passing <code>$result</code> in to <code>mysqli_affected_rows</code> you actually want to pass the DB link (returned by <code>mysqli_connect</code>) which will give you the number of rows affected by the previous query. See:

<a href="http://uk.php.net/mysqli_affected_rows" rel="noreferrer">http://uk.php.net/mysqli_affected_rows</a>

entityMap|blocks|key|7dnsj|text|echo+mysqli_affected_rows($dblink);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|21o0g|mysqli对象包含受影响行的计数，而不是结果集。我建议您使用带有OO风格的mysqli，或者尝试使用PDO。|unstyled^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$C|D]]|$2|E|4|F|6|G|8|I|9|@]|A|@]|B|$]]]]

<pre><code>echo mysqli_affected_rows($dblink);
</code></pre>

The mysqli object contains the count of the affected rows not the result set.
I recommend you to use mysqli with OO style or try PDO.

entityMap|blocks|key|275ip|text|您应该只给出|type|unstyled|depth|inlineStyleRanges|entityRanges|data|aebgn|(在您的情况下|akp68|)，而不是|54i9b|在您编写的代码中。^0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|I|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|J|9|@]|A|@]|B|$]]|$2|E|4|F|6|7|8|K|9|@]|A|@]|B|$]]|$2|G|4|H|6|7|8|L|9|@]|A|@]|B|$]]]]

You should only give the <code>$mysqli_link</code> (in your case <code>$dblink</code>) , not the <code>$result</code> in the code that you have written.

entityMap|blocks|key|9e3hi|text|你想知道选定的行数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|fl6fe|应用于INSERT、UPDATE、REPLACE或DELETE查询|csqbr|(受影响|8gjb9|_|3l1i|行PHP.net)|2qsus|..。|4a855|对于SELECT查询(您想要的)，有|8e5l2|5961l|(数量|bjp2r|klqu|hgl0|..。如您所见，num|btb6c|dkbbg|应在SELECT查询的结果上使用行。|dem2v|你想要的是|fokhq|它给出了选定的行数。|g54q|下面是它们的用法示例：|eik9o|$mysqli+=+new+mysqli("localhost",+"my_user",+"my_password",+"world");

$mysqli->query("CREATE+TABLE+Language+SELECT+*+from+CountryLanguage");
echo+"Affected+rows+(INSERT):+"+.+$mysqli->affected_rows;+//+$mysqli+is+the+link+variable+to+the+DB

$result+=+$mysqli->query("SELECT+Code,+Name+FROM+Country+ORDER+BY+Name");
echo+"Selected+rows:+"+.+$result->num_rows;+//+Here+we+use+the+$result+variable+from+the+query|code-block|syntax|javascript^0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|19|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|1A|9|@]|A|@]|B|$]]|$2|E|4|F|6|7|8|1B|9|@]|A|@]|B|$]]|$2|G|4|H|6|7|8|1C|9|@]|A|@]|B|$]]|$2|I|4|J|6|7|8|1D|9|@]|A|@]|B|$]]|$2|K|4|L|6|7|8|1E|9|@]|A|@]|B|$]]|$2|M|4|N|6|7|8|1F|9|@]|A|@]|B|$]]|$2|O|4|-4|6|7|8|1G|9|@]|A|@]|B|$]]|$2|P|4|Q|6|7|8|1H|9|@]|A|@]|B|$]]|$2|R|4|H|6|7|8|1I|9|@]|A|@]|B|$]]|$2|S|4|J|6|7|8|1J|9|@]|A|@]|B|$]]|$2|T|4|U|6|7|8|1K|9|@]|A|@]|B|$]]|$2|V|4|H|6|7|8|1L|9|@]|A|@]|B|$]]|$2|W|4|X|6|7|8|1M|9|@]|A|@]|B|$]]|$2|Y|4|Z|6|7|8|1N|9|@]|A|@]|B|$]]|$2|10|4|11|6|7|8|1O|9|@]|A|@]|B|$]]|$2|12|4|13|6|7|8|1P|9|@]|A|@]|B|$]]|$2|14|4|15|6|16|8|1Q|9|@]|A|@]|B|$17|18]]]]

You want to the number of the selected rows.
<code>mysqli::$affected_rows</code> should be used for INSERT, UPDATE, REPLACE or DELETE queries <a href="https://www.php.net/manual/en/mysqli.affected-rows.php" rel="nofollow noreferrer">(affected_rows PHP.net)</a>.
For SELECT queries (what you want) there is <code>mysqli_result::$num_rows</code> <a href="https://www.php.net/manual/en/mysqli-result.num-rows.php" rel="nofollow noreferrer">(num_rows PHP.net)</a>.
As you see num_rows should be used on the result from the SELECT query.
What you want is <code>echo mysqli_num_rows ( $result )</code> which gives you the number of the selected rows.
An example for the usage from both of them:
<pre><code>$mysqli = new mysqli(&quot;localhost&quot;, &quot;my_user&quot;, &quot;my_password&quot;, &quot;world&quot;);

$mysqli-&gt;query(&quot;CREATE TABLE Language SELECT * from CountryLanguage&quot;);
echo &quot;Affected rows (INSERT): &quot; . $mysqli-&gt;affected_rows; // $mysqli is the link variable to the DB

$result = $mysqli-&gt;query(&quot;SELECT Code, Name FROM Country ORDER BY Name&quot;);
echo &quot;Selected rows: &quot; . $result-&gt;num_rows; // Here we use the $result variable from the query
</code></pre>

entityMap|blocks|key|akc2d|text|echo+mysqli_num_rows($result);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|6thn3|这应该是可行的。|unstyled^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$C|D]]|$2|E|4|F|6|G|8|I|9|@]|A|@]|B|$]]]]

<pre><code>echo mysqli_num_rows($result);
</code></pre>

This should work.

I am working on making server side validation for a form. Using AJAX, the form sends the value in the input field for 'username' to my php page which then checks to see if this username already exists in the database.

Here is my php code:

<pre><code>$result = mysqli_query($dblink, "SELECT * FROM users WHERE `username` = '$regname'") 
or die(mysqli_error($dblink));
echo mysqli_affected_rows($result);
</code></pre>

*(At the moment I am doing a simple echo for the mysqli_affected_rows just to see if my MySQL query is working as intended)*

The error I am getting is:

<blockquote>
 Warning: mysqli_affected_rows() expects parameter 1 to be mysqli, object given in /Users/test/Sites/proj/formvalidate.php on line 20
</blockquote>

I am not quite sure what this error is trying to tell me. From what I have Googled "object" is a reference to OOP programming methods, but (as far as I know) I am not using OOP concepts/principles in this particular example? Or did I misinterpret this error message?

Thank you.

How to get the number of rows from a SELECT query? Error: mysqli_affected_rows() expects parameter 1 to be mysqli, object given

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

教程

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云智能顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

EdgeOne AI 安全实战专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

聚焦“写作效率、视觉美观与运行性能”三方面进行全面升级，为您提供更高效、稳定的创作环境

社区富文本&Markdown编辑器全新改版上线，欢迎大家体验!

诚挚邀请您参与本次调研，分享您的真实使用感受与建议。您的反馈至关重要，感谢您的支持与参与！

社区新版编辑器体验调研

 我正在做一个表单的服务器端验证工作。使用AJAX，表单将' username‘输入字段中的值发送到我的php页面，然后该页面检查该用户名是否已经存在于数据库中。 这是我的php代码： $result = mysqli_query($dblink, "SELECT * FROM users WHERE `username` = '$regname'") or die(mysqli_error($d

问mysqli_affected_rows()要求参数1为mysqli，给定对象
EN

回答 5

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问mysqli_affected_rows()要求参数1为mysqli，给定对象EN

回答 5

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问mysqli_affected_rows()要求参数1为mysqli，给定对象
EN