How To Connect WordPress database with other SQL Database?

Good Day,

I hope someone could help me! I have a wordpress site for my client and plugin called leagueengine installed, this site is for football, my client has a database software where he adds football results he wants me to connect the database of his software to the plugin database so that once he update them in the software automatically updated in league plugin. Can I do that! please help or advice..

Thank you..