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POPlay2's Ebean Notation to Create Models
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copied!<p>Ebean is using a very similar JPA annotation to map objects into a database. I've been checking out <code>@OneToOne @OneToMany @ManyToMany @ManyToOne</code> relationships.</p> <p>I just learned that inverse field is very inefficient (when use <code>@mappedBy</code> to determine a bidirectional relationship). </p> <p>I know normally, if I don't use ORM and just use SQL to create my own database structure, when I encounter this problem:</p> <p>Articles <-> Tags</p> <p>This is a many to many relationship. An article can have many tags, and one tag can be attached to many articles.</p> <p>Normally, with SQL, I will create a Article table and a Tag table. Then I will create a separate table with two columns:</p> <p>Article_Tag Table:</p> <pre><code>PrimaryKey ID (int) ArticleID (int) ForeignKey to Article Table TagID (int) ForeignKey to Tag Table </code></pre> <p>Article Table:</p> <pre><code>PrimaryKey ArticleID (int) Article Title (varchar) </code></pre> <p>Tag Table:</p> <pre><code>PrimaryKey TagID (int) Tag Title (varchar) </code></pre> <p>My only problem now is how should/can I translate/rewrite this with Ebean(JPA) notation?</p> <p>First, do I need to create a model named Article_Tag in order for this Article_Tag table or is it created by Ebean automatically?</p> <p>Second, how should I annotate my article model and my tag model to describe this relationship? Which one is <code>@mappedBy</code> which one?</p> <p>Third, if I use <code>@mappedBy</code>, will it generate inverse field? Should I and how do I avoid using it?</p>

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