Single registration/login for two database systems

Howdy. I’ve been plugging away at learning php and a little mysql and last night I had the bright idea to connect two databases in some way. I have been working with WordPress and a LMS called efront for the purpose of learning. They both have user tables that contain much of the same info but with different field names. Would I use mysql to create a form that injects registration information into both tables and then verify the data in both tables with a user login form that looks to both tables? What kind of changes would have to be made to both database connection strings? If any? Thanks for any input

i hv such experience when i need to single sign-on into my custom built member area and SMF forum, after doing what u mentioned, “injects registration information into both tables and then verify the data in both tables with a user login form that looks to both tables”, but gave up and ended up using CURL method.

much easier than trying to “change both database connection strings” and "injects registration information "

I’m not familiar with CURL. Can you direct me to a script or something I can start with?