There is a basic book information table, and a field in the table is designed as whether it is already in book management.

There is a borrowing data record table to record borrowing data. When inserting data, the sign whether the book is in the library is not in the library.

There is a book return data record table, which records the data of book return. When inserting data, the sign of whether the book is in the library is updated to be in the library.