25-动态SQL之Foreach

动态SQL之Foreach

接口

//查询第1-2-3号记录的博客
    List<Blog> queryBlogForeach(Map map);

对应的xml

<!--select * from mybatis.blog where 1=1 and (id=1 or id=2 or id=3)-->
<select id="queryBlogForeach" parameterType="map" resultType="blog">
    select * from mybatis.blog
    <where>
        <foreach collection="ids" item="id" open="and (" close=")" separator="or">
            id=#{id}
        </foreach>
    </where>
</select>

测试

    @Test
    public void queryBlogForeach(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        BlogMapper mapper = sqlSession.getMapper(BlogMapper.class);
        HashMap  map= new HashMap();
        ArrayList<Integer> ids = new ArrayList<Integer>();
        ids.add(1);
        ids.add(2);
        ids.add(3);
        map.put("ids",ids);
        List<Blog> blogs = mapper.queryBlogForeach(map);
        for (Blog blog : blogs) {
            System.out.println(blog);
        }
        sqlSession.close();
    }