在MyBatis的对象中持久化集合

本文介绍了在MyBatis的对象中持久化集合的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有POJO类：

class Ticket { private int id; private double cost; private Date time; private List<Place> places; // Getters and setters here } class Place { private int row; private int place; // Getters and setters here }

创建一张票和一些地方：

Then I create one ticket and some places:

Ticket ticket = new Ticket(); ticket.setCost(58.7); ticket.setTime(new Date()); Place place1 = new Place(); place1.setRow(1); place1.setPlace(2); ticket.addPlace(place1); Place place2 = new Place(); place2.setRow(3); place2.setPlace(4); ticket.addPlace(place2);

现在我想把它保存到DB：

And now I want to save it to DB:

session.insert("insertTicket", ticket); sessionmit();

在MapperConfig.xml中，我写这行：

In MapperConfig.xml I write this lines:

<insert id="insertTicket" parameterType="Ticket"> INSERT INTO tickets (cost, time) VALUES (#{cost}, #{time}) </insert>

如何以自动模式保存列出地点？ MyBatis可以为我保存吗？ 或者我需要用 foreach 手动迭代，并手动插入 Place ？

How I can save List places in automatic mode? Does MyBatis can save it for me? Or I need to iterate manually with foreach and insert every Place by hand?

任何帮助。

推荐答案

尽管MyBatis能够支持相反的方向（即在查询期间填充列表，或从连接），则不存在将包含列表插入数据库的自动模式。

Even though MyBatis is able to support the reverse direction (i.e. filling the list during a query with a nested select or from a join), there is no automatic mode that inserts the containing list into the database.

根据此 Google网上论坛讨论，您必须手动插入列表元素。

According to this Google Groups discussion you have to insert the list elements manually.