Esta extensión fue declarada obsoleta en PHP 5.5.0 y eliminada en PHP 7.0.0. En su lugar debería utilzarse las extensiones MySQLi o PDO_MySQL. Véase también la guía MySQL: elegir una API. Las alternativas a esta función son:

Para compilar, simplemente usar la opción de configuración --with-mysql[=DIR] donde opcionalmente [DIR] apunta al directorio de instalación de MySQL.

Aunque esta extensión de MySQL es compatible con MySQL 4.1.0 y superior, no da soporte a las funcionalidades extra que estas versiones proveen. Para ello usar la extensión MySQLi.

Si se quisiera instalar la extensión de MySQL junto con la extensión MySQLi se debe usar la misma libreria de cliente para evitar cualquier conflicto.

Instalación en Sistemas Linux

Nota: [DIR] es la ruta a los ficheros de la biblioteca cliente de MySQL (cabeceras y bibliotecas), los cuales se pueden descargar desde » MySQL.

Matriz de soporte en tiempo de compilación de ext/mysql
Versión de PHP Por defecto Opciones de configuración: mysqlnd Opciones de configuración: libmysqlclient Historial de cambios
4.x.x libmysqlclient No Disponible --without-mysql to disable MySQL habilitada por omisión, las bibliotecas cliente de MySQL están incluidas
5.0.x, 5.1.x, 5.2.x libmysqlclient No Disponible --with-mysql=[DIR] MySQL ya no está habilitada de forma predeterminada, y las bibliotecas cliente de MySQL ya no están integradas
5.3.x libmysqlclient --with-mysql=mysqlnd --with-mysql=[DIR] mysqlnd ahora está disponible
5.4.x mysqlnd --with-mysql --with-mysql=[DIR] mysqlnd ahora es el predeterminado

Instalación en sistemas Windows

PHP 5.0.x, 5.1.x, 5.2.x

MySQL ya no está activado por defecto, así la DLL php_mysql.dll debe ser habilitada dentro de php.ini. Además, PHP necesita acceso a la libreria de cliente de MySQL. Un archivo llamado libmysql.dll que está incluido en la distribución de PHP de Windows, y así PHP se comunica con MySQL, este fichero necesita estar disponible en el PATH de los sistemas Windows. Para información sobre como hacerlo ver el FAQ titulado "Cómo agrego mi directorio de PHP a PATH en Windows". Aunque copiando libmysql.dll al directorio del sistema de Windows también funcionará (ya que el directorio del sistema está por defecto en el PATH del sistema), pero no está recomendado.

Como ocurre con cualquier otra extensión de PHP (tal como php_mysql.dll), la directiva de PHP extension_dir, debe establecer el directorio donde estan localizada las extensiones de PHP. Ver también el Manual de instrucciónes de instalación en Windows. Un ejemplo de valor de extension_dir para PHP 5 es c:\php\ext


Si al iniciar el servidor web se produce un error similar al siguiente: "Unable to load dynamic library './php_mysql.dll'", esto se debe a que php_mysql.dll y/o libmysql.dll no puede ser encontrado por el sistema.

PHP 5.3.0+

El Controlador Nativo de MySQL está habilitado por omisión. Incluya php_mysql.dll, pero libmysql.dll ya no es necesario o usado.

Notas de la instalación de MySQL


Se pueden encontrar errores y problemas de inicio de PHP al cargar esta extensión en conjunción con la extensión recode. Para más información ver la extension recode.


Si fueran necesarios otro juego de caracteres distinto de latin (predeterminado), se ha de instalar externamente (no incluido) libmysqlclient con el soporte para el juego de caracteres compilado.

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User Contributed Notes 7 notes

heneryville at gmail dot com
13 years ago
I believe that this is happens especially with Windows 7. As far I I've been able to tell XP and Vista come with this line enabled, but windows 7 comments it out and notes that the DNS will handle this.
15 years ago
In windows systems, the same error "unable to load dynamic library php_mysql.dll" will happen, if there's an old version of the file in the "windows\system32" folder.
Either remove it or update it.
buzzr515 at gmx dot de
13 years ago
i've experienced a similar (if not the same) problem.

to enable the mysql_... and mysqli_... funtionality, i opened the php.ini file to uncomment the following lines:

but phpinfo() still stated that no mysql extensions were loaded.
i tried the fixes and suggestions above with no success.
so i invoked the windows shell and typed ("Path" environment variable set to the PHP & MySQL directories):
php.exe -m

this returned the following error: "PHP Startup: Unable to load dynamic library 'C:\php5\php_mysql.dll' - Module not found."

this told me that PHP didn't recognize what i thought was the extensions directory. it searched all other places first (sys-dir, workin'-dir, the MySQL "bin" dir because of the "Path" variable set, and even a curious directory "C:\php5" that doesn't even exist on my mashine) but not the expected "ext" directory.

so the fix was to go to "php.ini" again and uncomment the following line:

this fixed it for me.
so if module loading is done improperly, first of all check the "Path" environment variable and the "php.ini" file - especially the "extension_dir" config value - and check if all values are set to their correct values.

hope this helps any1.

OS: Win7 Ultimate x86
Apache v2.2.16
PHP v5.3.3
MySQL v5.1.50
mail dot umlcat at gee mail dot com
10 years ago
Could not install mysql, on windows, had several conflicts or bugs.

In order to solve it:

* Used the "libmysql.dll" provided by PHP zip files, not the one that comes with Mysql, the mysql file had to be moved or deleted from its folder. Put it on the "apache/bin" folder, altought some use it in "windows" folder.

* Originally, moved "*mysql*.dll" files from its extension folder, and returned back.

* enabled mysql driver extensions in the "php.ini" file, but also enabled some extensions, that seemed not to be required, but, it did, like "php_openssl.dll" or "php_pdo.dll" on an early version of php.

Added the "PHPIniDir xxx"" to the "httpd.conf" apache config. file, where xxx is the path to the folder where the "php.ini" file is located, and make sure its the same.

Be warned, that this fixes, may help or not, for your installation, since there are many ways to configure the same thing (to solve a problem).
Steve in Weston-Super-Mare
12 years ago
I had problems when moving from a version of PHP that used the isapi dll to the fast cgi version. The script to register the script maps compained that there was already a script map in place.

I went to the IIS control panel, right clicked on websites and removed the php association in the Home Directory | Configuration screen.

However, the fastcgi script still complained about existing script map. Finally I tracked it down, I had to right click on Default Web Site and clear out the php mappings from there too.

Then it all worked, except that for some strange reason, the php.ini file that gets picked up is the one from my old PHP directory, not the latest upgrade one. But this can be detected by running phpinfo which shows the loaded php.ini file so I knew which one to amend with the fastcgi options.

Bit of a hassle to figure it all out but it does work in the end.
amatsak at gmail dot com
14 years ago
I have experienced exactly the same problem as flo_stefi at yahoo dot com below. It appears that instead of loading libmysql.dll that came with the PHP package, the PHP engine was loading libmySQL.dll located in MySQL's bin directory, which was causing Apache to crash.

I fixed the problem by renaming MySQL's libmySQL.dll into libmySQL_renamed.dll. Now PHP loads the library that came with its package and everything works fine.
o dot kochetilov at gmail dot com
12 years ago
Please note that libmySQL.dll in MySQL bin directory should be renamed in order to use right library (that comes with PHP).
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