mybatis of the inquiry and paging java

There are ways to search in 1.mybatis 3 Zhong

//查询单个值
    @Test
    public void testFindOne()throws IOException{
        SqlSession session = MybatisUtil.getSqlSession();
        User user = (User)session.selectOne("cn.sxt.vo.UserMapper.findOne", 1);
        System.out.println(user);
        session.close();
    }
    //查询list
    @Test
    public void testFindAll() throws IOException{
        SqlSession session = MybatisUtil.getSqlSession();
        List<User> list = session.selectList("cn.sxt.vo.UserMapper.findAll");
        for(User u:list){
            System.out.println(u);
        }
        session.close();
    }
    //查询map
    @Test
    public void testFindMap()throws IOException{
        SqlSession session = MybatisUtil.getSqlSession();
        //selectMap 传递的参是 map集合的key值。
        Map map=session.selectMap("cn.sxt.vo.UserMapper.findMap", "name");
        for(Iterator iter=map.keySet().iterator();iter.hasNext();){
            Object key=iter.next();
            System.out.println(key+"---"+map.get(key));
        }
        session.close();
    }

Mapping file

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.sxt.vo.UserMapper">
    <!-- 查询单个对象 -->
    <select id="findOne" resultType="User">
        select * from t_user where id=#{id}
    </select>
    <!-- 查询list -->
    <select id="findAll" resultType="User">
        select * from t_user
    </select>
    <!-- 查询map -->
    <select id="findMap" resultType="Map">
        select * from t_user where id=1
    </select>
    <!-- 
        begin=(currentPage-1)*pageSize
        size=pageSize
     -->
    <select id="page1" resultType="User">
        select * from t_user limit #{begin},#{size}
    </select>
    <select id="pageRow" resultType="User">
        select * from t_user
    </select>
</mapper>

2. Paging

mybatis There are three ways to implement paging

Mapping file

    <select id="page1" resultType="User">
        select * from t_user limit #{begin},#{size}
    </select>
    <select id="pageRow" resultType="User">
        select * from t_user
    </select>

Code

// paged by sql statement, the object is passed as an argument
     @Test
     public  void TestPage () throws IOException { 
        the SqlSession the session = MybatisUtil.getSqlSession ();
         PageInfo PI = new new PageInfo (); 
        pi.setBegin ( . 3 ); 
        PI. the setSize ( . 3 ); 
        List . <the User> List = the session selectList is ( "cn.sxt.vo.UserMapper.page1" , PI );
         for (the User U: List) { 
            System.out.println (U); 
        } 
    } 
    / / paging through sql statement, parameters are passed in map
    @Test
    public void testPage1() throws IOException{
        SqlSession session = MybatisUtil.getSqlSession();
        Map map = new HashMap();
        map.put("begin", 0);
        map.put("size", 3);
        List<User> list = session.selectList("cn.sxt.vo.UserMapper.page1",map);
        for(User u:list){
            System.out.println(u);
        }
    }
    //通过RowBounds来实现分页 
    @Test
    public void testPage2 () throws IOException { 
        the SqlSession the session = MybatisUtil.getSqlSession ();
         // The first parameter corresponds to the index, the second parameter number of records per
         RowBounds bounds = new new RowBounds (. 3,. 3 ); 
        List <the User> = session.selectList List ( "cn.sxt.vo.UserMapper. pageRow ", null , bounds );
         for (the User U: List) { 
            System.out.println (U); 
        } 
    }