Store a library card related information, set the library card ID number as the primary key, and store the library card related information in other fields;
One table stores book information, with the book ID as the primary key, and other fields store information related to books.
A table stores borrowing records, and the record ID is set as the primary key. Other fields store: library card ID, primary key corresponding to library card table ID, primary key corresponding to book table ID, borrowing time and other information.
New, cancelled and modified library cards should be operated on the library card form, and books-related operations should be operated on the library card form. Book ID, library card ID, newly generated book record ID, borrowing time and new record should be saved respectively.