问题
I have just installed a MySQL server (version 3.23.58) on an old RedHat7. I cannot install a more recent MySQL version because of the dependencies. I cannot update librairies on this RedHat server.
However, I have a problem connecting to the database with PHP. First I used PDO but I realized that PDO was not compatible with MySQL 3.23...
So I used mysql_connect(). Now I have the following error:
Warning: mysql_connect(): No such file or directory in /user/local/apache/htdocs/php/database.php on line 9
Error: No such file or directory
My code is:
$host = 'localhost';
$user = 'root';
$password = '';
$database = 'test';
$db = mysql_connect($host, $user, $password) or die('Error : ' . mysql_error());
mysql_select_db($database);
I checked twice that the database exists and the login and password are correct.
This is strange because the code works fine on my Windows PC with Wampp. I cannot figure out where the problem comes from.
Any idea?
回答1:
Yes you can not connect like that!
@PLB and @jammypeach mysqli is after v4.1, he is using v3 :) Guys read the specs, if you want really to help!
You can't connect, because your socket file is a bit wrong. I remember now that the old RH had this issue before. Your socket is probably as /var/mysql/mysql.sock or /tmp/mysql.sock but one or more apps are looking for the other.
If yours is /tmp/mysql.sock but no /var/mysql/mysql.sock you should:
cd /var
mkdir mysql
cd mysql
ln -s /tmp/mysql.sock mysql.sock
If you have /var/mysql/mysql.sock but no /tmp/mysql.sock then:
cd /tmp
ln -s /var/mysql/mysql.sock mysql.sock
You'll need permissions to make the changes. Just sudo, if needed before the commands above!
ANOTHER SOLUTION (easier):
Create file and call phpinfo(); Look for 'mysql.default_socket'; or 'pdo_mysql.default_socket'; Open My.ini or My.cnf find the socket value e.g. socket=/tmp/mysql.sock Open your php.ini file (which is also found on your phpinfo() page as ‘Loaded Configuration File‘) and change all the occurrences of the incorrect socket location to the correct socket location from MySQL.
ANOTHER SOLUTION (easiest): DSN for PDO:
mysql:unix_socket=/tmp/mysql.sock;dbname=...
mysql_connect:
$db = mysql_connect('localhost:/tmp/mysql.sock', ...
Your system is really scary when it comes to security, if you're hosting sensitive data, I'd upgrade to the latest versions.
---- UPDATE ----
Aaahhhh PHP 5.0 and MySQL 3.23 :)
PHP 5 has a mysql client packaged that cannot connect to a MySQL database less than version 4.1. Starting with version 4.1, MySQL uses a new way of password hashing that is not compatible with pre-4.1 databases. The server your configuration is connecting to is version 3.23. So you need to get yourself a higher version of MySQL. Sorry, but there is no other practical solution for your case. If I was you, I'd upgrade the whole system and install the most recent OS version, if I had to I'd go with Debian and the most recent stable versions of PHP and MySQL.
回答2:
On a MAC OSX just restart the mysql server
sudo /usr/local/mysql/support-files/mysql.server restart
It worked for me
回答3:
Fortunatly this is worked well for me:
$db = mysql_connect('localhost:/var/lib/mysql/mysql.sock', 'Username', 'Password');
回答4:
I had a similar issue that took me several hours to solve. I placed Mysql / Mariadb on a separate drive and the PHP driven website was looking for the socket in the default location. So, I created a symbolic link but I think SELinux would not give the permission. So, then I added these lines to the /etc/php.ini file and it works.
pdo_mysql.default_socket = /data/mysql/mysql.sock
mysql.default_socket = /data/mysql/mysql.sock
mysqli.default_socket = /data/mysql/mysql.sock
回答5:
I use MAMP and has the sample problem. I found that there are no mysql.sock in tmp. so use this code
cd /tmp && ln -s /Applications/MAMP/tmp/mysql/mysql.sock
It worked for me
来源：https://stackoverflow.com/questions/12584762/mysql-connect-no-such-file-or-directory