Phased summary of the research and development of the "library management system -" borrowing and returning "module

《 Library management system ——“ Borrow and return books ” modular 》 Phased summary of project research and development

Completion time of this task ：2021 year 8 month 2 Japan ～2021 year 8 month 10 Japan
Complete module functions ： Borrow and return books

One 、 Function realization

Borrowing and returning books mainly includes lending books 、 Function module of book return .
Book lending ： See the picture 1, It is the implementation interface of the library management module .

                                chart 1   Library management module 

If I click on the picture 1 Of “ Borrow books ” Button to pop up the modal box of book borrowing

At this time, you need to select the borrowing number , Make sure users can borrow books , Other content has been added automatically , And set it to the locked state of the input box , If it selects the borrowing number, continue to click Save , It will judge whether the borrowing inventory is greater than 0, If not greater than 0 Will show ,“ The library is saved as 0, Please find other books to borrow ”, That is, the borrowing inventory is greater than 0, It will further judge , Judge whether the number of books borrowed by this user is less than two . If there are less than two books, you can borrow them , You can't borrow more than two books .

As shown in the figure below Book return module

As can be seen in the picture , There are four buttons , The return , delay , overdue , Scrap , If I click to select a book borrowing record in the status of borrowing, the overdue will be disabled , Logically, it is , If the borrowing status is extended, then the extension and overdue will be disabled , If it is overdue , Returns and extensions will be banned . In the book returning module , The borrowing records whose borrowing status is return or scrap will not be displayed . Every time you open this module, you will request the controller as shown in the figure

Judge whether the borrowing time and returning time in the database have expired by comparing them with the current time , Some people may wonder why you don't modify the borrowing status at the same time when querying , First of all , Because not only the book returning module needs this judgment , The book borrowing record module also needs this judgment , If I write one each, it will be more troublesome , Let them open the module , Directly request the same controller to make a judgment .

second , At that time, I tried to judge and modify the borrowing status in the controller that returned the query , But there is a small problem , If you open the module for the first time , The data returned by the query is not the modified data, but the data before modification , This obviously leads to problems , Although such a problem will not be found after the second time , Or refresh it , But I feel this is not rigorous enough , So I used another controller to request data to update the borrowing status before querying .

     This is the first time to make a phased summary of project research and development , It may not be well written , Please forgive me a lot .

I sent it to my classmates ！