Undefined class constant 'MYSQL_ATTR_COMPRESS'

I get a 500 when visiting my site through a browser.

Output of nginx’s error.log:

2016/05/24 00:49:00 [error] 5647#5647: *1 FastCGI sent in stderr: "PHP message: Undefined class constant 'MYSQL_ATTR_COMPRESS'
PHP message: [app/main/db/database.php:49] DB\Database->connect('mysql:host=localhost;port=3306;dbname=','pathfinder','pathfinder','censored')
PHP message: [app/main/db/database.php:18] DB\Database->setDB('PF')
PHP message: [app/lib/base.php:35] ReflectionClass->newInstanceArgs(array('PF'))
PHP message: [app/main/controller/controller.php:56] Prefab::instance('PF')
PHP message: [app/lib/base.php:1652] Controller\Controller->beforeroute(Base::__set_state(array('hive'=>array('HEADERS'=>array('Accept-Language'=>'en-US,en;q=0.8,da;q=0.6','Accept-Encoding'=>'gzip, deflate, sdch','Dnt'=>'1','User-Agent'=>'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.108 Safari/537.36','Upgrade-Insecure-Requests'=>'1','Accept'=>'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8','Cache-Control'=>'max-age=0','Connection'=>'keep-alive','Host'=>'nobelnet.dk:5560'),'AGENT'=>'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.108 Safari/537.36','AJAX'=>false,'ALIAS'=>'login','ALIASES'=>array('setup'=>'/setup','login'=>'/','sso'=>'/sso/@action','map'=>'/map'),'AUTOLOAD'=>'app/main/','BASE'=>'','BITMASK'=>2,'BODY'=>'','CACHE'=>'folder=tmp/cache/','CASELESS'=>true,'CONFIG'=>NULL,'CORS'=>array('headers'=>'','origin'=>false,'credentials'=>false,'expose'=>false,'ttl'=>0),'DEBUG'=>3,'DIACRITICS'=>a...
PHP message: [app/lib/base.php:1486] Base->call(array(ControllerAppController::__set_state(array()),'init'),array(Base::__set_state(array('hive'=>array('HEADERS'=>array('Accept-Language'=>'en-US,en;q=0.8,da;q=0.6','Accept-Encoding'=>'gzip, deflate, sdch','Dnt'=>'1','User-Agent'=>'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.108 Safari/537.36','Upgrade-Insecure-Requests'=>'1','Accept'=>'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8','Cache-Control'=>'

I suspect I might have a wrong MySQL version (or wrong php extension?). Somehow it works when I run the app before nginx (directly running php index.php).

Any idea?

[Tupsi]

check your php.ini for your fpm installation. Seems your missing the mysql pdo plugin there. It seems to be enabled for the cli installation and thats why its working “directly”. The /setup page should have told you if you have a supported mysql/php installation. It is flashy red when not, so you really cant miss it! .-) check this out: http://stackoverflow.com/questions/2424343/undefined-class-constant-mysql-attr-init-command-with-pdo

[Jpine89]

Ran into this issue 3 years later. Was able to figure out the issue, my mysql and php weren’t talking to each other.

apt-get update apt-get install php7.2-mysql

Fixed the issue for me.