MyBatis使用注解开发实现过程详解

public class UserMapperTest {
  @Test
  public void test(){
    SqlSession sqlSession = MyBatisUtils.getSqlSession();
    //底层主要应用反射
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    List users = mapper.getUsers();
    for (User user : users) {
      System.out.println(user);
    }
    sqlSession.close();
  }
}

public static SqlSession getSqlSession(){
  return sqlSessionFactory.openSession(true);
}

public interface UserMapper {
  @Select(value = "select * from user")
  List getUsers();

  //方法存在多个参数，所有的参数前面必须加上@Param注解
  @Select("select * from user where id = #{id} or name = #{name}")
  User getUserByID(@Param("id")int id,@Param("name")String name);

  @Insert("insert into user(id,name,pwd) values (#{id},#{name},#{password})")
  int addUser(User user);

  @Update("update user set name = #{name},pwd = #{password} where id = #{id}")
  int updateUser(User user);

  @Delete("delete from user where id = #{uid}")
  int deleteUser(@Param("uid") int id);
}