Put content from files into database

I've got several json files following the same structure (two different types of structure, files are named '[login to view URL]). They all are in the same directory. The content of each file should be put in a database. While adding a new line, you should also check wheter it isn't already in the database. If it is, you should check wheter there is a changed value anywhere in the file. If there is, the content of the old value should go in a linked table with archived values for that table. Is nothing is changed, nothing should be done with the line. If the line is not present, it should be added to the relational database of course. Shouldn't be too hard for an experienced python programmer... Sample files and uml scheme for database on request.