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POWhen is persistence.xml necessary for Play 2.1.1 Java? Entities don't persist in a many-to-one relationship
 

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  1. POWhen is persistence.xml necessary for Play 2.1.1 Java? Entities don't persist in a many-to-one relationship
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    <p>In my program, I have a Task model with a <code>allDates</code> field, which is a collection of all the Dates that task occurs on. My goal is to make a calendar manager that allows users to input tasks that repeat on certain days.</p> <p>In Tasks, I defined a OneToMany relation between a task and its dates in <a href="https://github.com/six5532one/calpractice2/blob/repeatingEvents/app/models/Task.java" rel="nofollow noreferrer">line 34</a>. To treat the elements of <code>allDates</code> as an entity, I wrapped each date in a DateHelper model that is another Ebean entity.</p> <p>Right before I save the Task, my console output indicates someTask.allDates.size() is accurate and a number greater than one. After I save the task, however:</p> <p>1) I query DateHelpers in <a href="https://github.com/six5532one/calpractice2/blob/repeatingEvents/app/models/Task.java" rel="nofollow noreferrer">line 194</a> for all DateHelper instances for a given task, and the server only returns the first DateHelper that was added to someTask.allDates, rather than returning the same number of DateHelpers that was added to the task before I saved.</p> <p>2) someTask.allDates.size() also returns 1, and the only element in allDates is the first DateHelper I added before saving the task.</p> <p>I read <a href="https://stackoverflow.com/questions/6257284/play-framework-jpa-how-to-implement-one-to-many-relationship">here</a> and <a href="http://www.playframework.com/documentation/2.1.1/JavaJPA" rel="nofollow noreferrer">here</a> that Play developers should modify a persistence.xml file to integrate with JPA. Do I need to do this if I am importing ebean? Also, my program successfully maps one User to many Tasks, so I am confused about why the OneToMany mapping does not work for one Task to many TaskHelpers.</p>
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    1. USEmily Chen
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