yl-backend/src/main/java/com/guwan/backend/service/impl/BookServiceImpl.java

package com.guwan.backend.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.guwan.backend.entity.Book;
import com.guwan.backend.mapper.BookMapper;
import com.guwan.backend.service.BookService;
import com.mongoplus.conditions.query.LambdaQueryChainWrapper;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Slf4j
@Service
@RequiredArgsConstructor
public class BookServiceImpl implements BookService {

    private final BookMapper bookMapper;

    @Override
    @Transactional
    public Book addBook(Book book) {


     //   new LambdaQueryWrapper<>()

      //          new LambdaQueryChainWrapper<>()

        bookMapper.insert(book);
        return book;
    }

    @Override
    @Transactional
    public Book updateBook(Book book) {
        bookMapper.updateById(book);
        return book;
    }

    @Override
    @Transactional
    public void deleteBook(Long id) {
        bookMapper.deleteById(id);
    }

    @Override
    public Book getBookById(Long id) {
        return bookMapper.selectById(id);
    }

    @Override
    public Book getBookByIsbn(String isbn) {
        return bookMapper.selectOne(
            new LambdaQueryWrapper<Book>()
                .eq(Book::getIsbn, isbn)
        );
    }

    @Override
    public IPage<Book> getBookList(Integer pageNum, Integer pageSize, String keyword) {
        LambdaQueryWrapper<Book> wrapper = new LambdaQueryWrapper<>();
        if (keyword != null && !keyword.isEmpty()) {
            wrapper.like(Book::getTitle, keyword)
                  .or()
                  .like(Book::getAuthor, keyword)
                  .or()
                  .like(Book::getDescription, keyword);
        }
        return bookMapper.selectPage(new Page<>(pageNum, pageSize), wrapper);
    }

    @Override
    public IPage<Book> getBooksByCategory(String category, Integer pageNum, Integer pageSize) {
        LambdaQueryWrapper<Book> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(Book::getCategory, category);
        return bookMapper.selectPage(new Page<>(pageNum, pageSize), wrapper);
    }
}