Unfortunately this one bit me for a good half day.
Placing libmysql.dll in the php/ext directory did not work. I tested this under 5.6.2. You need to have it somewhere in the PATH or in SYSTEM or SYSTEM32. But to me this is very silly to force the user to have to setup environment variables or move DLLs around. It shouldn't have to go that far and be the responsibility of the setup program and/or developer.
I really think this issue could be solved doing this:
1) Installer/distribution bundle all three files together under one directory (ext) - php_mysql.dll/php_mysqli.dll/libmysql.dll
2) Developer goes into php_mysql.dll/php_mysqli.dll and in DllMain() on DLL_PROCESS_ATTACH:
LoadLibrary ("./libmysql.dll");
Then you don't have to deal with this problem and neither do your users.
Kerry Kobashi
Installation
For compiling, simply use the --with-mysql[=DIR] configuration option where the optional [DIR] points to the MySQL installation directory.
Although this MySQL extension is compatible with MySQL 4.1.0 and greater, it doesn't support the extra functionality that these versions provide. For that, use the MySQLi extension.
If you would like to install the mysql extension along with the mysqli extension you have to use the same client library to avoid any conflicts.
Installation on Linux Systems
PHP 4
The option --with-mysql is enabled by default. This default behavior may be disabled with the --without-mysql configure option. If MySQL is enabled without specifying the path to the MySQL install DIR, PHP will use the bundled MySQL client libraries.
Users who run other applications that use MySQL (for example, auth-mysql) should not use the bundled library, but rather specify the path to MySQL's install directory, like so: --with-mysql=/path/to/mysql. This will force PHP to use the client libraries installed by MySQL, thus avoiding any conflicts.
Installation on Windows Systems
PHP 4
The PHP MySQL extension is compiled into PHP.
PHP 5+
MySQL is no longer enabled by default, so the php_mysql.dll DLL must be enabled inside of php.ini. Also, PHP needs access to the MySQL client library. A file named libmysql.dll is included in the Windows PHP distribution and in order for PHP to talk to MySQL this file needs to be available to the Windows systems PATH. See the FAQ titled "How do I add my PHP directory to the PATH on Windows" for information on how to do this. Although copying libmysql.dll to the Windows system directory also works (because the system directory is by default in the system's PATH), it's not recommended.
As with enabling any PHP extension (such as php_mysql.dll), the PHP directive extension_dir should be set to the directory where the PHP extensions are located. See also the Manual Windows Installation Instructions. An example extension_dir value for PHP 5 is c:\php\ext
Note: If when starting the web server an error similar to the following occurs: "Unable to load dynamic library './php_mysql.dll'", this is because php_mysql.dll and/or libmysql.dll cannot be found by the system.
MySQL Installation Notes
Crashes and startup problems of PHP may be encountered when loading this extension in conjunction with the recode extension. See the recode extension for more information.
Note: If you need charsets other than latin (default), you have to install external (not bundled) libmysql with compiled charset support.
Installation
02-Nov-2008 07:02
20-Jul-2008 02:05
This error also occurs if the windows path entry for an older version of MYSQL appears before the path entry for a late version of php. In which case the version of libmysl.dll in the MySQL bin directory will be found before the one bundled with php. Reversing the system path entries so php is first fixes this problem. e.g.
PATH= ... c:\php;C:\Program Files\MySQL\MySQL Server 4.1\bin
13-Jun-2008 09:37
In windows systems, the error "unable to load dynamic library php_mysql.dll" also happens if there's an old version of the file libmysql.dll in the "windows\system32" folder.
12-May-2008 12:42
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.
