A demonstration of how to use the MyBatisPlus pagination plugin IPage.

MyBatis Plus is an excellent enhanced tool for MyBatis, offering many practical features including pagination. Pagination allows for dividing a large amount of data into multiple pages for more efficient queries and reduced data transfer.

In MyBatis Plus, pagination queries are done using the IPage interface. IPage is a pagination plugin provided by MyBatis Plus, which includes methods and properties related to pagination queries. Below is an example code using IPage:

1. First of all, we need to define a method for pagination query as shown below:

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

    @Override
    public IPage<User> getUserListByPage(int pageNum, int pageSize) {
        // 创建分页对象
        IPage<User> page = new Page<>(pageNum, pageSize);
        // 调用MyBatis Plus的分页查询方法
        IPage<User> userPage = baseMapper.selectPage(page, null);
        // 返回查询结果
        return userPage;
    }
}

1. In the code above, we first create a pagination object IPage page = new Page<>(pageNum, pageSize), where pageNum represents the current page number, and pageSize represents the number of records displayed per page. Then, we call the pagination query method baseMapper.selectPage(page, null) provided by MyBatis Plus, passing the pagination object and query conditions as parameters. Finally, we return the query results.
2. In the place where the paging query method is called, we can achieve pagination by calling the method getUserListByPage(pageNum, pageSize) as shown below:

@Autowired
private UserService userService;

@GetMapping("/users")
public Result getUserListByPage(@RequestParam("pageNum") int pageNum, @RequestParam("pageSize") int pageSize) {
    IPage<User> userPage = userService.getUserListByPage(pageNum, pageSize);
    return Result.success(userPage);
}

In the above code, we retrieve the paginated query results by calling the userService.getUserListByPage(pageNum, pageSize) method and return the results.

By utilizing the sample code above, we can observe that implementing pagination query using the IPage interface is very straightforward. Simply create a pagination object and call the pagination query method provided by MyBatis Plus. Additionally, the IPage interface also offers other practical methods such as retrieving the total number of records and total number of pages, which can be accessed based on actual requirements.