Home Backend Development PHP Tutorial Warning</b> mysql_free_result(): supplied argument is not a valid MySQL result,该怎么解决

Warning</b> mysql_free_result(): supplied argument is not a valid MySQL result,该怎么解决

Jun 13, 2016 pm 12:16 PM
gt mysql nbsp sql

Warning: mysql_free_result(): supplied argument is not a valid MySQL result
这是什么错?

<br /><?php<br />	header('content-type:application/json;charset=utf8');<br />	$host = '127.0.0.1:3307';<br />	$root = 'root';<br />	$pwd = 'apeg1996';<br /><br />	$con = mysql_connect($host,$root,$pwd);<br />	if($con == false){<br />		echo "连接数据库失败!"; <br />	}else{ <br />		echo "连接数据库成功!";<br />	}<br /><br />	$sql = "select * from user";<br />	function execute_data($sql){<br />		$result = mysql_query($sql);<br />		mysql_free_result($result);<br />		mysql_close($conn);<br />		return $result;<br />	}<br />	echo execute_data($sql);<br />?><br />
Copy after login


已显示连接成功,但是报这个错。。
<br />连接数据库成功!<br /><br /><b>Warning</b>:  mysql_free_result(): supplied argument is not a valid MySQL result resource in <b>F:\environment\WAMP\wamp5\wamp\wamp\www\test\sql.php</b> on line <b>17</b><br /><br /><br /><br /><b>Warning</b>:  mysql_close(): supplied argument is not a valid MySQL-Link resource in <b>F:\environment\WAMP\wamp5\wamp\wamp\www\test\sql.php</b> on line <b>18</b><br /><br />
Copy after login

------解决思路----------------------
你只连接了数据库系统,但没有选择待操作的数据库
mysql_select_db('库名');
否则怎么知道你在查询那个库中的 user 表呢?

另外,你的 mysql_close($conn) 在函数中,而 $conn 并未传到函数中。
所以会有第2条错误
------解决思路----------------------
本帖最后由 fdipzone 于 2015-03-15 00:05:08 编辑

引用:
Quote: 引用:

$result = mysql_query($sql);
改为
$result = @mysql_query($sql) or die(mysql_error());


网页上显示的是No database selected, 这个是没有找到这个数据库吗?
但是我用的是Navicat 8 for mysql 这个视图工具。
我在这里面创建的数据库,并简历了表。 我应该怎么去查询这个数据库里的表呢?


你在mysql_query之前没有mysql_select_db,mysql不知道你需要在哪个db中执行查询操作。

在创建连接后,加一句
@mysql_select_db('这里填写数据库名',$conn) or die(mysql_error());

<br /><?php<br />    header('content-type:application/json;charset=utf8');<br />    $host = '127.0.0.1:3307';<br />    $root = 'root';<br />    $pwd = 'apeg1996';<br /> <br />    $con = mysql_connect($host,$root,$pwd);<br />    if($con == false){<br />        echo "连接数据库失败!"; <br />    }else{ <br />        echo "连接数据库成功!";<br />    }<br /> <br />    @mysql_select_db('这里填写数据库名',$conn) or die(mysql_error());	 // 加入这句<br /><br />    $sql = "select * from user";<br />    function execute_data($sql, $conn){ // 加入$conn 参数<br />        $result = mysql_query($sql);<br />        mysql_free_result($result);<br />        mysql_close($conn);<br />        return $result;<br />    }<br />    echo execute_data($sql, $conn);<br />?><br />
Copy after login

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1664
14
PHP Tutorial
1268
29
C# Tutorial
1243
24
Laravel Introduction Example Laravel Introduction Example Apr 18, 2025 pm 12:45 PM

Laravel is a PHP framework for easy building of web applications. It provides a range of powerful features including: Installation: Install the Laravel CLI globally with Composer and create applications in the project directory. Routing: Define the relationship between the URL and the handler in routes/web.php. View: Create a view in resources/views to render the application's interface. Database Integration: Provides out-of-the-box integration with databases such as MySQL and uses migration to create and modify tables. Model and Controller: The model represents the database entity and the controller processes HTTP requests.

MySQL and phpMyAdmin: Core Features and Functions MySQL and phpMyAdmin: Core Features and Functions Apr 22, 2025 am 12:12 AM

MySQL and phpMyAdmin are powerful database management tools. 1) MySQL is used to create databases and tables, and to execute DML and SQL queries. 2) phpMyAdmin provides an intuitive interface for database management, table structure management, data operations and user permission management.

MySQL vs. Other Programming Languages: A Comparison MySQL vs. Other Programming Languages: A Comparison Apr 19, 2025 am 12:22 AM

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages ​​such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages ​​have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

Solve database connection problem: a practical case of using minii/db library Solve database connection problem: a practical case of using minii/db library Apr 18, 2025 am 07:09 AM

I encountered a tricky problem when developing a small application: the need to quickly integrate a lightweight database operation library. After trying multiple libraries, I found that they either have too much functionality or are not very compatible. Eventually, I found minii/db, a simplified version based on Yii2 that solved my problem perfectly.

Laravel framework installation method Laravel framework installation method Apr 18, 2025 pm 12:54 PM

Article summary: This article provides detailed step-by-step instructions to guide readers on how to easily install the Laravel framework. Laravel is a powerful PHP framework that speeds up the development process of web applications. This tutorial covers the installation process from system requirements to configuring databases and setting up routing. By following these steps, readers can quickly and efficiently lay a solid foundation for their Laravel project.

Solve MySQL mode problem: The experience of using the TheliaMySQLModesChecker module Solve MySQL mode problem: The experience of using the TheliaMySQLModesChecker module Apr 18, 2025 am 08:42 AM

When developing an e-commerce website using Thelia, I encountered a tricky problem: MySQL mode is not set properly, causing some features to not function properly. After some exploration, I found a module called TheliaMySQLModesChecker, which is able to automatically fix the MySQL pattern required by Thelia, completely solving my troubles.

MySQL: Structured Data and Relational Databases MySQL: Structured Data and Relational Databases Apr 18, 2025 am 12:22 AM

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL: Key Features and Capabilities Explained MySQL: Key Features and Capabilities Explained Apr 18, 2025 am 12:17 AM

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

See all articles