PHP connection MySQL Error "No such file or directory"

1. 
   The first is to determine the mysql_connect() mysql_pconnect() problem, the fault phenomenon is that the function returns NULL, and mysql_error() returns "No such file or directory".
   
   
2. Write a phpinfo page, find mysql.default_socket , mysqli.default_socket , pdo_mysql.default_socket .
   
   
3. Start MySQL (see note 2), execute command STATUS; Note the value of the UNIX socket.
   
   
   
   
4. If the values of 2 and 3 are different, open php.ini (where you can find php.ini from the Phpinfo page, by default /private/etc/php.ini ), and change the value of the three configuration items mentioned in 2 to 3.
   
   
   (Note that there are three changes, namely: mysql.default_socket ,, mysqli.default_socket pdo_mysql.default_socket )
   
   
5. Restart Apache.
   
   
   
   OK, here is the mistake to rule out.

PHP connection MySQL Error "No such file or directory"