1、resultmap中的一对一，一对多的使用

(1)resultmap的使用方法java

(2)resultmap的使用样例web

SELECT

o.id as orderId,

user_id as userId,

u.username as username,

number as numId,

od.id AS orderDetail ,

od.items_id as itemId

FROM

orders o

LEFT JOIN orderdetail od ON o.id = od.orders_id

left join user u on o.user_id=u.id

三、vo类app

@Data

public class OrderVO {

private String orderId;

private String numId;

private UserVO user;

private List orderDetailId;

private List orderDetail;

}

@Data

public class UserVO {

private String id;

private String username;

private String password;

private String phone;

}

@Data

public class OrderDetail {

private String id;

private String itemId;

}