touch
/Library/LaunchDaemons/com.mysql.mysql.plist

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> 
<plist version="1.0"> 
  <dict> 
    <key>KeepAlive</key> 
    <true/> 
    <key>Label</key> 
    <string>com.mysql.mysqld</string> 
    <key>ProgramArguments</key> 
    <array> 
    <string>/usr/local/mysql/bin/mysqld_safe</string> 
    <string>--user=root</string> 
    </array>   
  </dict> 
</plist> 

sudo launchctl load -w /Library/LaunchDaemons/com.mysql.mysql.plist