添加用户收藏书籍、取消收藏书籍、获取书籍收藏状态功能（后端+数据库）；更新Api文档

bookshelfplus/src/main/java/plus/bookshelf/Dao/Mapper/UserFavoritesDOMapper.java

@@ -0,0 +1,69 @@
+package plus.bookshelf.Dao.Mapper;
+
+import plus.bookshelf.Dao.DO.UserFavoritesDO;
+
+public interface UserFavoritesDOMapper {
+    /**
+     * This method was generated by MyBatis Generator.
+     * This method corresponds to the database table user_book_favorites_relation
+     *
+     * @mbg.generated
+     */
+    int deleteByPrimaryKey(Integer id);
+
+    /**
+     * This method was generated by MyBatis Generator.
+     * This method corresponds to the database table user_book_favorites_relation
+     *
+     * @mbg.generated
+     */
+    int insert(UserFavoritesDO record);
+
+    /**
+     * This method was generated by MyBatis Generator.
+     * This method corresponds to the database table user_book_favorites_relation
+     *
+     * @mbg.generated
+     */
+    int insertSelective(UserFavoritesDO record);
+
+    /**
+     * This method was generated by MyBatis Generator.
+     * This method corresponds to the database table user_book_favorites_relation
+     *
+     * @mbg.generated
+     */
+    UserFavoritesDO selectByPrimaryKey(Integer id);
+
+    /**
+     * This method was generated by MyBatis Generator.
+     * This method corresponds to the database table user_book_favorites_relation
+     *
+     * @mbg.generated
+     */
+    int updateByPrimaryKeySelective(UserFavoritesDO record);
+
+    /**
+     * This method was generated by MyBatis Generator.
+     * This method corresponds to the database table user_book_favorites_relation
+     *
+     * @mbg.generated
+     */
+    int updateByPrimaryKey(UserFavoritesDO record);
+
+    /**
+     * 通过用户id和书籍id删除用户收藏状态
+     * @param userId
+     * @param bookId
+     * @return
+     */
+    int deleteByUserIdAndBookId(Integer userId, Integer bookId);
+
+    /**
+     * 通过用户id和书籍id获取用户收藏状态
+     * @param userId
+     * @param bookId
+     * @return
+     */
+    UserFavoritesDO selectCountByUserIdAndBookId(Integer userId, Integer bookId);
+}