mybatis实现使用原生的sql

1.相应的xml文件中

<select id="selectByCategories" resultType="map" parameterType="java.lang.String" >
${_parameter}
</select>

2.对应的mapper文件中添加下列方法

List<Map<String , Long>> selectByCategories(String sql);

3.在业务层写相应的逻辑

// 得到不同分类下的相同文章
	public List<ArticleInfo> getTheSameArticle(String args){

	  String[] arr = args.split(",");
	   int len=arr.length;
		String sql="select article_id from"
				+ " (select category_id,article_id from article_category WHERE category_id in ("+args
				+ ")  GROUP BY category_id,article_id)b GROUP BY article_id HAVING count(category_id)="+len;
		 System.out.println(sql);
		 List <Map<String, Long>> resultList=articleCategoryMapper.selectByCategories(sql );
		System.out.println(resultList);
		LinkedList<ArticleInfo> articleList=new LinkedList<>();
		for (int i=0;i<resultList.size();i++) {
			System.out.println(resultList.get(i));
			Map<String, Long> tempMap = resultList.get(i);	
			System.out.println(tempMap.get("article_id"));
			long id=tempMap.get("article_id");
		   articleList.add(getOneById(id));		
		}

		return articleList;
		   
		
			
		
	}

　成功。