Backend Development
PHP Tutorial
How to Securely Update a MySQL Database Using the MySQLi Extension in PHP?
How to Securely Update a MySQL Database Using the MySQLi Extension in PHP?
Dec 15, 2024 am 01:04 AM
Perfect MySQL Extension Code Sample
The goal of this question is to provide a concise and secure PHP code sample using the MySQL extension. The code should avoid common errors associated with the mysql_* functions, including:
- SQL injection
- Broken error reporting
- Cross-site scripting (XSS) injections
Code Sample:
<?php
header('Content-type: text/html; charset=utf-8');
error_reporting(E_ALL | E_STRICT);
ini_set('display_errors', 1);
$config = [
'host' => '127.0.0.1',
'user' => 'my_user',
'pass' => 'my_pass',
'db' => 'my_database'
];
$connection = @mysql_connect($config['host'], $config['user'], $config['pass']);
if (!$connection) {
trigger_error('Unable to connect to database: ' . mysql_error(), E_USER_ERROR);
}
if (!mysql_select_db($config['db'])) {
trigger_error('Unable to select db: ' . mysql_error(), E_USER_ERROR);
}
if (!mysql_set_charset('utf8')) {
trigger_error('Unable to set charset for db connection: ' . mysql_error(), E_USER_ERROR);
}
$result = mysql_query(
'UPDATE tablename SET name = "' . mysql_real_escape_string($_POST['name']) . '" WHERE id = "' . mysql_real_escape_string($_POST['id']) . '"'
);
if ($result) {
echo htmlentities($_POST['name'], ENT_COMPAT, 'utf-8') . ' updated.';
} else {
trigger_error('Unable to update db: ' . mysql_error(), E_USER_ERROR);
}
?>
Explanation:
- This code connects to the MySQL database using mysql_connect() and specifies the database to use with mysql_select_db().
- The mysql_set_charset() function is used to set the character set for the connection to UTF-8.
- The SQL update query is constructed using placeholders and the mysql_real_escape_string() function to prevent SQL injection.
- The query result is checked, and the message "$name updated." is displayed if the update was successful. Otherwise, an error is triggered.
- Error reporting is enabled to allow for better debugging during development. In production mode, this setting can be disabled to suppress PHP error messages to the end user.
Note that this code sample is provided as a reference and should not be considered a complete solution for all PHP applications. It is recommended to use PDO extension for modern MySQL applications, as it provides enhanced security and performance.
The above is the detailed content of How to Securely Update a MySQL Database Using the MySQLi Extension in PHP?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How do I implement authentication and authorization in PHP?
Jun 20, 2025 am 01:03 AM
TosecurelyhandleauthenticationandauthorizationinPHP,followthesesteps:1.Alwayshashpasswordswithpassword_hash()andverifyusingpassword_verify(),usepreparedstatementstopreventSQLinjection,andstoreuserdatain$_SESSIONafterlogin.2.Implementrole-basedaccessc
How do I stay up-to-date with the latest PHP developments and best practices?
Jun 23, 2025 am 12:56 AM
TostaycurrentwithPHPdevelopmentsandbestpractices,followkeynewssourceslikePHP.netandPHPWeekly,engagewithcommunitiesonforumsandconferences,keeptoolingupdatedandgraduallyadoptnewfeatures,andreadorcontributetoopensourceprojects.First,followreliablesource
What is PHP, and why is it used for web development?
Jun 23, 2025 am 12:55 AM
PHPbecamepopularforwebdevelopmentduetoitseaseoflearning,seamlessintegrationwithHTML,widespreadhostingsupport,andalargeecosystemincludingframeworkslikeLaravelandCMSplatformslikeWordPress.Itexcelsinhandlingformsubmissions,managingusersessions,interacti
How to set PHP time zone?
Jun 25, 2025 am 01:00 AM
TosettherighttimezoneinPHP,usedate_default_timezone_set()functionatthestartofyourscriptwithavalididentifiersuchas'America/New_York'.1.Usedate_default_timezone_set()beforeanydate/timefunctions.2.Alternatively,configurethephp.inifilebysettingdate.timez
How do I install PHP on my operating system (Windows, macOS, Linux)?
Jun 20, 2025 am 01:02 AM
The method of installing PHP varies from operating system to operating system. The following are the specific steps: 1. Windows users can use XAMPP to install packages or manually configure them, download XAMPP and install them, select PHP components or add PHP to environment variables; 2. macOS users can install PHP through Homebrew, run the corresponding command to install and configure the Apache server; 3. Linux users (Ubuntu/Debian) can use the APT package manager to update the source and install PHP and common extensions, and verify whether the installation is successful by creating a test file.
How do I validate user input in PHP to ensure it meets certain criteria?
Jun 22, 2025 am 01:00 AM
TovalidateuserinputinPHP,usebuilt-invalidationfunctionslikefilter_var()andfilter_input(),applyregularexpressionsforcustomformatssuchasusernamesorphonenumbers,checkdatatypesfornumericvalueslikeageorprice,setlengthlimitsandtrimwhitespacetopreventlayout
How do I destroy a session in PHP using session_destroy()?
Jun 20, 2025 am 01:06 AM
To completely destroy a session in PHP, you must first call session_start() to start the session, and then call session_destroy() to delete all session data. 1. First use session_start() to ensure that the session has started; 2. Then call session_destroy() to clear the session data; 3. Optional but recommended: manually unset$_SESSION array to clear global variables; 4. At the same time, delete session cookies to prevent the user from retaining the session state; 5. Finally, pay attention to redirecting the user after destruction, and avoid reusing the session variables immediately, otherwise the session needs to be restarted. Doing this will ensure that the user completely exits the system without leaving any residual information.
What is data serialization in PHP (serialize(), unserialize())?
Jun 22, 2025 am 01:03 AM
ThePhpfunctionSerialize () andunserialize () AreusedtoconvertcomplexdaTastructdestoresintostoraSandaBackagain.1.Serialize () c OnvertsdatalikecarraysorobjectsraystringcontainingTypeandstructureinformation.2.unserialize () Reconstruct theoriginalatataprom
