MyBatis注解——一对一

1、订单对应用户：一对一 ，数据库

CREATE TABLE `orderinfo` (
  `id` int(11) DEFAULT NULL,
  `ordertime` datetime DEFAULT NULL,
  `total` decimal(8,2) DEFAULT NULL,
  `uid` int(11) DEFAULT NULL
);


CREATE TABLE `user` (
  `id` int(11) DEFAULT NULL,
  `username` varchar(50) DEFAULT NULL
);

2、实体

public class OrderInfo {

    private Integer id;

    private Date ordertime;

    private Double total;

    private Integer uid;

    private UserInfo user;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Date getOrdertime() {
        return ordertime;
    }

    public void setOrdertime(Date ordertime) {
        this.ordertime = ordertime;
    }

    public Double getTotal() {
        return total;
    }

    public void setTotal(Double total) {
        this.total = total;
    }

    public Integer getUid() {
        return uid;
    }

    public void setUid(Integer uid) {
        this.uid = uid;
    }

    public UserInfo getUser() {
        return user;
    }

    public void setUser(UserInfo user) {
        this.user = user;
    }

    @Override
    public String toString() {
        return "OrderInfo{" +
                "id=" + id +
                ", ordertime=" + ordertime +
                ", total=" + total +
                ", uid=" + uid +
                ", user=" + user +
                '}';
    }
}

public class UserInfo {

    private Integer id;

    private String username;

    private List orderInfoList;

    private List roleList;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public List getOrderInfoList() {
        return orderInfoList;
    }

    public void setOrderInfoList(List orderInfoList) {
        this.orderInfoList = orderInfoList;
    }

    public List getRoleList() {
        return roleList;
    }

    public void setRoleList(List roleList) {
        this.roleList = roleList;
    }

    @Override
    public String toString() {
        return "UserInfo{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", orderInfoList=" + orderInfoList +
                ", roleList=" + roleList +
                '}';
    }
}

3、maper 接口

public interface OrderMapper {

    @Results({
            @Result(property = "id",column = "id"),
            @Result(property = "ordertime",column="ordertime"),
            @Result(property = "total",column="total"),
            @Result(property = "user",column = "uid",javaType = UserInfo.class,
                    one = @One(select = "com.deppon.mapper.UserMapper.findUserById"))
    })
    @Select("select * from orderinfo")
    public List findOrderList();

}

public interface UserMapper {
    //List findAllUsers();

    @Select("select * from user")
    List findUserList();

    @Insert("insert into user values(#{id},#{username})")
    void addUser(UserInfo userInfo);

    @Update("update user set username = #{username} where id = #{id}")
    void update(UserInfo userInfo);

    List findAllUserAndRole();

    @Select("select * from user where id = #{id}")
    UserInfo findUserById(Integer id);
}

4、测试类

public class TestOrderMapperUtil {

    private OrderMapper orderMapper;

    @Before
    public void before() throws IOException {
        String path = "SqlConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(path);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession(true);
        orderMapper = session.getMapper(OrderMapper.class);
    }

    @Test
    public void test(){
        List orderList = orderMapper.findOrderList();
        System.out.println(orderList);
    }
}

备注：使用注解开发，核心配置文件中应该配置

授予root用户增删改查权限，密码：123456

mysql>grant select,delete,update,create,drop on *.* to root@"%" identified by "123456";