Off topic:mySQL won't start and I could not use Perl API for ensembl

Question

[2015rpro]

Could anyone share with me how to correctly install MySQL for perl API for ensembl? I have tried the whole day and it did not work.When I run "mysql" on terminal and it keeps showing the following message.

Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

And when I run sudo /usr/local/mysql/support-files/mysql.server start, It keeps displaying the following message

.................... ERROR! The server quit without updating PID file (/usr/local/mysql/data/Macintosh-2.pid).