This section is so difficult! !

Question

Let God give me some guidance

Answer 1

In fact, it just removes all the records from the database, then determines how many pages there are based on the number of items displayed on each page, uses a variable to record the current page number, and at the same time determines which piece of data should be output. Okay, as for the next page and the previous page, just set the boundaries of the previous variables 1 and -1 at the same time, and do not exceed the calculated page number