Creating rows in multiple tables using one form

Hi!

I’m setting up a system which our organisation can use to keep track of our members. Our organisation also has a web-library (managed with the WebLibrarian WordPress plugin), where each member has a library id the can use to borrow books.

I want to create a form which creates a row in our “members” table, and a row in our “library_patrons” table (that is part of the WebLibrarian plugin). Since the data stored in these two tables has significant overlap (name, address etc.), it would be convenient to have to only input the information once.

I’ve tried setting up a parent-child relationship (though our case is more 1:1 rather than 1:many) but I can only seem to set up a form or import data for either the parent table or the child table, and not both at the same time. The way I have it at the moment is that the “members” table contains a column “library_id” which corresponds to a unique key “id” field in the “library_patrons” table

An alternative would be if there was a way to automate creating rows, so when the “members” table is updated, a new row is added to the “library_patrons” table, based on the new row in in “members”.