在MyBatis的对象中持久化集合 [英] Persist collection in object with MyBatis

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);
session.commit();

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.

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