【UserMapper.xml】和之前的作对比

           
           
               SELECT * FROM USER WHERE user.sex =#{userCustom.sex} AND user.username LIKE '%${userCustom.username}%'               
           
               SELECT * FROM USER                                                                and user.sex=#{userCustom.sex}                                                          and user.username LIKE '%${userCustom.username}%'                                                 
     

 

【UserMapper.java】接口

public interface UserMapper {        //用户信息综合查询findUserList    public List
     
       findUserList(UserQueryVo userQueryVo) throws Exception;//动态SQL：用户信息综合查询findUserList2    public List
      
        findUserList2(UserQueryVo userQueryVo) throws Exception;}
      
     

 

【UserMapperTest.java】测试

/**      * 用户信息的综合查询     * @throws Exception     */    @Test    public void testFindUserList2() throws Exception {                SqlSession sqlSession =sqlSessionFactory.openSession();                 //创建一个UserMapper对象,Mybatis自动生成mapper代理对象        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);                //创建包装对象，设置查询条件        UserQueryVo userQueryVo=new UserQueryVo();        UserCustom userCustom=new UserCustom();                userCustom.setSex("1");        userCustom.setUsername("6");   //这两句分别被注释，将会忽略被注释的条件进行查询                userQueryVo.setUserCustom(userCustom);                //调用UserMapper的方法        List
     
       list=userMapper.findUserList2(userCustom);   //传入的参数为null时，不会进行查询，且不会报错！！！之前的方式传入参数为null会报错            System.out.println(list.size());    }