安装/配置
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安装

编译时，只要使用 --with-mysql[=DIR] 配置选项即可，其中可选的 [DIR] 指向 MySQL 的安装目录。

虽然本 MySQL 扩展库兼容 MySQL 4.1.0 及其以后版本，但是它不支持这些版本提供的额外功能。要使用这些功能，请使用 MySQLi 扩展库。

如果要同时安装 mysql 扩展库和 mysqli 扩展库，必须使用同一个客户端库以避免任何冲突。

在 Linux 系统下安装

Note: [DIR] is the path to the MySQL client library files (headers and libraries), which can be downloaded from » MySQL.

ext/mysql compile time support matrix
PHP 版本 默认 配置选项: mysqlnd 配置选项: libmysql 更新日志
4.x.x libmysql 不适用 --without-mysql to disable MySQL enabled by default, MySQL client libraries are bundled
5.0.x, 5.1.x, 5.2.x libmysql 不适用 --with-mysql=[DIR] MySQL is no longer enabled by default, and the MySQL client libraries are no longer bundled
5.3.x libmysql --with-mysql=mysqlnd --with-mysql=[DIR] mysqlnd is now available
5.4.x mysqlnd --with-mysql --with-mysql=[DIR] mysqlnd is now the default

在 Windows 系统下安装

PHP 4

PHP MySQL 扩展已经编译入 PHP。

PHP 5+

MySQL 默认未启用，因此必须在 php.ini 中激活 php_mysql.dll 动态连接库。此外，PHP 还需要访问 MySQL 客户端连接库。PHP 的 Windows 发行版包括了一个 libmysql.dll，为了让 PHP 能和 MySQL 对话，此文件必须放在 Windows 的系统路径 PATH 中。怎样做见 FAQ 中的“怎样把 PHP 目录加入到 Windows 路径中”。尽管将 libmysql.dll 拷贝到 Windows 系统目录中也可以（因为系统目录默认在系统路径 PATH 中），但不推荐这样做。

要激活任何 PHP 扩展库（例如 php_mysql.dll），PHP 指令 extension_dir 要被设为 PHP 扩展库所在的目录。参见手工 Windows 安装指南。PHP 5 下 extension_dir 取值的一个例子是 c:\php\ext。

Note:

如果启动 web 服务器时出现类似如下的错误："Unable to load dynamic library './php_mysql.dll'"，这是因为系统找不到 php_mysql.dll 和／或 libmysql.dll。

MySQL 安装注意事项

Warning

当同时加在本扩展库和 recode 扩展库时 PHP 可能会崩溃。更多信息见 recode 扩展库。

Note:

如果需要不同于 latin（默认值）的字符集，必须安装外部的（非绑定的）已编译入所需字符集支持的 libmysql。

安装/配置
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用户评论:

Steve in Weston-Super-Mare (27-Jul-2011 06:55)

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.

o dot kochetilov at gmail dot com (30-Apr-2011 08:39)

Please note that libmySQL.dll in MySQL bin directory should be renamed in order to use right library (that comes with PHP).

buzzr515 at gmx dot de (03-Sep-2010 05:13)

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:
;extension=php_mysql.dll
;extension=php_mysqli.dll
;extension=php_pdo_mysql.dll

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:
;extension_dir="ext"

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

titus at antennasystems dot com (28-Jun-2010 06:00)

I ran into the soon to be infamous problem of upgrading to PHP 5.3.x.
The way I found to resolve the issue was to

1: Do "mysql_upgrade" on the server (to make MySQL compliant with MySQL 4.1+).

2: Modify my.cf to not use old passwords:
(Just comment out "old_passwords=1")
#old_passwords=1

3: Change the root password so you can properly connect to the server:
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('enter_new_password_here');

http://dev.mysql.com/doc/refman/5.1/en/old-client.html
http://tinyurl.com/mysql-old-password

Taken from http://www.comsiteconstruction.com/blueonyx-modifications

samishiikihaku23 at gmail dot com (17-Jun-2010 07:36)

I've checked all the 5.3 distribution files from http://windows.php.net/ for the "libmysql.dll" file that this article claims is in the distributions.

None of the 5.3 dist. supplies "libmysql.dll". Download the recent 5.2 release for the file.

heneryville at gmail dot com (30-Apr-2010 09:32)

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.

jez300 (10-Mar-2010 01:34)

Windows 7 / Vista:

This took me hours to realise... If you receive the message:
Warning: mysql_connect(): [2002] A connection attempt failed because the connected party did not (trying to connect via tcp://localhost:3306)

You may need to map localhost to your IP address (127.0.0.1) which is used to find your Mysql server.

Edit {systemdrive}:\Windows\System32\drivers\etc

Make sure "127.0.0.1       localhost" isn't commented out with # at the begining of the line!

-----

You may also like to know that if you change from MySQL 32 bit to 64 bit and the Mysql service wont start you may need to rename or delete your Mysql data
{systemdrive}:\ProgramData\x MySQL\MySQL Server 5.1\data

Regards,

Jez.

amatsak at gmail dot com (22-Jun-2009 10:46)

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.

flo_stefi at yahoo dot com (01-Apr-2009 12:10)

I had a problem to make mysql work with php on Windows. Using mysql-5.1.32-win32 and php-5.2.9-1-win32-installer I've installed mysql and php. All seemed to be ok (phpinfo displayed the right information) but when running a basic script mysql_connect(..) the apache ends with a stupid error like "[Wed Apr 01 14:44:05 2009] [notice] Parent: child process exited with status 3221225477 -- Restarting.".
I manage to fix it by using instead of libMySQL.dll from mysql package another version (libmysql.dll) I had from a previous installation.

lobbanhousehold at gmail dot com (12-Feb-2009 03:05)

I figured my problem why php and mysql weren't working together even though they worked independent of each other. PHP was configured with IIS 5.1 (XP) using the php5isapi.dll file.

I also set system variables in PATH adding the locations of both php and mysql folders. I also moved the mysql DLL files from ext folder to the root folder of php.

I discovered that php would not work with mysql if php folder was not located on the C:\ (i.e. C:\php). I also renamed the libmysql.dll that came with mysql so that the system would not see it, and moved the one that came with php to C:\WINDOWS\system32.

After I did this last paragraph i was able to see MySQL and MySQLi sections listed in phpinfo() which indicates MySQL is finally enabled

admin at kobashicomputing dot com (02-Nov-2008 07:02)

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

rogerc at clubsites dot net (20-Jul-2008 03:05)

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

Mahesh (13-Jun-2008 10:37)

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.

jonnus (12-May-2008 01:42)

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.