Avaje-EBean-部分对象查询禁用延迟加载 [英] Avaje - EBean - Partial Object Query disable Lazy Loading

问题描述

我正在使用Play开发一个应用！框架2.1.3，使用EBean作为模型层，我希望能够执行部分对象查询，并且当我序列化为JSON以将结果发送回用户时，不需要按需延迟加载未选择的属性. /p>

我尝试将AutoFetch设置为false，我还尝试在序列化为JSON之前结束事务(最终导致Transaction is Inactive错误)，我还在模型类上添加了注释@Lazy(false). /p>

在同一注上，我也有一个一对多关联，我想查询它的前三行，我使用了new FetchConfig().queryFirst(2)，但是我想由于同样的延迟加载问题，我最终得到了整个相关的关联行.

我在阅读手册时读到了这本书( EBean Partial Objects ):

在以下情况下，部分对象将按需延迟加载其余数据: 您获得或设置了它没有的属性.

有没有解决的办法，我尝试过的一切似乎都不起作用！

解决方案

我通过在不需要懒加载的查询上使用标准的JDBC接口(Statements和ResultSets)解决了此问题. /p>

请注意，在Scala中，直接字段访问不使用延迟加载，但是不幸的是，这不是我在应用程序中使用的语言.

I'm developing an app using Play! Framework 2.1.3, using EBean for the model layer I wanna be able to execute a Partial Object Query and not have the un-selected properties lazy loaded on demand when I serialize to JSON in preparation to send the result back to the user.

I have tried setting AutoFetch to false, I have also tried to end the transaction before serializing to JSON (I ended up getting a Transaction is Inactive error) I've also added the annotation @Lazy(false) on my model class.

On the same note, I also have a One-to-Many association, and I wanna Query the first 3 rows of it, I used new FetchConfig().queryFirst(2) but I guess due to the same lazy loading issue, I end up getting the whole related association rows.

Looking at the manual, I read this (EBean Partial Objects):

A Partial Object will lazy load the rest of the data on demand when you get or set a property it does not have.

Is there a way around this, nothing I tried seemed to work!

解决方案

I have solved this issue by using the standard JDBC interface using Statements and ResultSets on the queries that I require not to have lazy loading on.

As a side note, turns out that in the case of Scala, direct field access does not use Lazy Loading, but unfortunately it is not the language I am using for my application.

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