Confusing PDO-only problem : Can't connect thr

问题:

So the problem changed from what it was, i'll leave the original question below to prevent bad reviews on answers like I had after someone editing his question I answered :

So I am working on a (really lame) shared hosting which has PDO installed, but it doesn't work. With default parameters

<?php
try {
    $dbh = new PDO('mysql:host=localhost;dbname=THE_DB_NAME', 'THE_USER', 'THE_PASSWORD');
    echo 'Connected to database';
    }
catch(PDOException $e)
    {
    echo $e->getMessage();
    }
?>

it throws this message :

SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

With a simple mysql_connect, it works.

And the socket path seems correct (both phpinfo and this query :

show variables like 'socket';

confirm.

Localhost redirects to 10.103.0.14 (this data comes from mysql_get_host_info() and in phpMyAdmin)

In the PDO, if i replace localhost by 127.0.0.1 i will get

SQLSTATE[HY000] [2003] Can't connect to MySQL server on '127.0.0.1' (111) 

And if i replace localhost by 10.103.0.14 :

Access denied for user 'USER_NAME'@'10.103.0.14' (using password: YES

Both IP adress (127.0.0.1 and 10.103.0.14) work with mysql_connect.

So apparently the problem comes from the PDO connection.

Does somebody knows where this could come from, or/and any way to fix it ?

Some server datas :

The PHP Version : 5.2.10 You can see the server's phpinfo : http://web.lerelaisinternet.com/abcd.php?v=5 No command line possible. (i know it should be the tech suport's job, but they're reaaaaaly slow)

Thanks

Previous question :

How to find the mysql.sock on a shared host (tricky way needed...)

So today's problem is : The PDO connection doesn't work on a shared host, and it's supposed to (it's installed on the server). Just a basic PDO connection :

<?php
try {
    $dbh = new PDO('mysql:host=localhost;dbname=THE_DB_NAME', 'THE_USER', 'THE_PASSWORD');
    echo 'Connected to database';
    }
catch(PDOException $e)
    {
    echo $e->getMessage();
    }
?>

throws this message :

SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

A regular mysql connection :

mysql_connect("localhost", "THE_USER", "THE_PWD") or die(mysql_error()); 
mysql_select_db("24DLJLRR1") or die(mysql_error());;
echo 'Connected to database <br/>';

works fine.

So apparently it cannot find the .sock. I think specifying the correct address should work, i tried some "classic" mysql path that I found on internet, without success. The phpinfo says it is at this adress (/var/lib/mysql/mysql.sock) (The PHP Version is 5.2.10) You can see the server's phpinfo : http://web.lerelaisinternet.com/abcd.php?v=5

So i am trying to figure out where the hell it is !!! I tried to look in the phpMyAdmin interface, but i couldn't find the info, plus it seems that phpMyAdmin connects to a different server (it has a different IP adress, and trying to connect to it with php gives a "Wrong password" error). The mysql_connect also connects to this adress, i think it redirects to a different server with some internal password/login.

Well if you have any idea of how to obtain this info (the provider's technical support is "fixing the problem"... it's been 1 month...). Also maybe the problem comes from somewhere else, but the same stuff works on other shared hosts...

The need of PDO is because I use the Symfony framework with Doctrine for this website, and the Doctrine plugin needs PDO... I don't want to redo the website from scratch !

Thanks for your help !

回答1:

This was already marked as answered, but not really solved (without changing databases). So, just in case someone like me also experiences this problem...

The easiest way to fix this is to first get the socket path (either by looking in the php.ini file or by using: phpmyadmin or the console (or construct it in mysql or mysqli)

...to run the following query (anything but PDO):

show variables like 'socket';       //as mentioned by symcbean

THEN, in the PDO connection string, change it to use the socket instead of a hostname:

$dbc = new PDO("mysql:unix_socket=/var/run/mysqld/mysqld.sock;dbname=$DBName", $User, $Password, array(PDO::ATTR_PERSISTENT => true)); // using persistent connections

This worked for me.

回答2:

FWIW, I had this issue and changed my host from 'localhost' to '127.0.0.1'.

I have no clue why localhost wasn't working, but that did the trick.

Odd thing is, we have tons of servers and it works on almost every one using 'localhost'

回答3:

Is your server running with SeLinux enabled (enforcing)? If it is, try running as root:

# setsebool -P httpd_can_network_connect on

回答4:

Can you try 127.0.0.1 as the server name instead of localhost?

IIRC, with some mySQL drivers / adapters, this decides whether the socket is used for establishing the connection or not.

回答5:

Using the connection which works, run the query:

show variables like 'socket';

(this behaves just like a select statement)...and you'll get the path of the running socket.

Then check the file permissions.

回答6:

I had the problem that production version worked just fine and a test version wasn't able to connect PDO :/ both versions was located at same servers, test in a sub directory.

The fix was replacing in DSN the localhost for ip.

'mysql:host=localhost;dbname=db'

became

'mysql:host=127.0.0.1;dbname=db'

回答7:

try:

exec('`which mysql_config` --socket');

this should show you the configured socket.

回答8:

I found the reason for the strange behaviour. If bind-address is different to 127.0.0.1 or 0.0.0.0 (all addresses) PDO can't connect to 127.0.0.1.

回答9:

For what it's worth, I found this page after having the exact same issue. I am on a server running Apache & PHP only - MySQL is installed on another machine. I tried both the DNS name of the server and its IP and confirmed I could ping it. A PHP app on the same machine is talking to the database fine, using old syntax mysql_connect( ). But PDO from the CLI was throwing this error.

The solution for me was to check my DSN. Any typo in the DSN itself is ignored silently, and PDO assumes you mean localhost. My issue was I had "name=" instead of "dbname=" in the DSN.

回答10:

The Issue In the Mysql configuration It you need to disable the option of skip-networking in my.conf configuration file this should work fine reference http://www.wolfcms.org/forum/post7098.html#p7098

回答11:

I just solved a similar issue. My guess is you probably replaced your mysql_connect() statement with the PDO equivalent. Don't forget you still have lots of other code dependent on that old connection statement. Try keeping the mysql_connect in place while writing in the PDO code.

回答12:

What worked for me was specifying the port number like so:

mysql:hostname;port=3306;dbname=dbname;

This got it to work when connecting to a local database. Now I'm working on getting it to work with a remote db.

回答13:

My problem may be different to the OP, but I thought it was worth posting. I did a software upgrade on a VM, then rebooted and got the OP's error message. It turned out to be an out-of-memory problem preventing mysql from starting. Deleting a few large files made the problem go away.

回答14:

One year later, I found a solution for this issue : using a SQLite database. PDO worked fine, but not with MySQL

** EDIT ** as everyone is downvoting this: This solved my issue (I'm the OP). I was using Doctrine, so switching RDBMS was easy and quick. Also the website was some a home made CMS, with very few trafic, so SQLite was fine.

I know it's not a real "Answer" to the problem, but if someone is in the same context: a crappy shared hosting which you can't change with this weird PDO-MySQL bug AND is using doctrine. This IS a solution. I can delete this answer, but if I had thought of this at the time of the OP, I would have saved a lot of time.