Undefined class constant 'MYSQL_ATTR_INIT_COMMAND' with pdo

Solution 1:

I just had the same error (with PHP 5.2.6), and all I had to do is enable the MySQL-specific PDO driver:

TL;DR

In your php.ini file, you should have the following line (uncommented):

• extension=php_pdo_mysql.dll on Windows
• extension=php_pdo_mysql.so on Linux/Mac

Longer explanation:

1. open php.ini in a text editor

   • _{e.g. its default path on Windows: C:\Program Files (x86)\PHP\v5.X\php.ini (substitute v5.x with the version you installed) or C:\Windows\php.ini, etc.}
   • _{or on Linux: /etc/php5/apache2/php.ini (e.g. this is the path on Ubuntu) or /etc/php5/cli/php.ini, /etc/php5/cgi/php.ini, etc.}
   • _{or you can get to know where it is like this:}
     • _{php --ini | find /i "Loaded" in Windows command prompt OR}
     • _{php --ini | grep "Loaded" in Linux/Mac terminal}
     • _{using phpinfo(), and looking for the line "Loaded Configuration File"}

2. and remove the semicolon from the beginning of the following line (to uncomment it):

   • ;extension=php_pdo_mysql.dll on Windows
     • OR ;extension=php_pdo_mysql.so on Linux/Mac
   • of course, if this line doesn't exist, you should paste it
   • so as a result the expected line would look like this in php.ini:
     • extension=php_pdo_mysql.dll on Windows
     • OR extension=php_pdo_mysql.so on Linux/Mac

3. You may need to restart your web server.

That solved my problem.

Solution 2:

I got the same error, on debian6, when I had not yet installed php5-mysql.

So I installed it, then restarted apache2

apt-get install php5-mysql
/etc/init.d/apache2 restart

Then the error went away.

If you have the same error on Ubuntu, instead of:

/etc/init.d/apache2 restart  

Type:

service apache2 restart