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POSLICK How to define bidirectional one-to-many relationship for use in case class
 

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    <p>I am using SLICK 1.0.0-RC2. I have defined the following two tables Directorate and ServiceArea where Directorate has a one to many relationship with ServiceArea </p> <pre><code>case class Directorate(dirCode: String, name: String) object Directorates extends Table[Directorate]("DIRECTORATES") { def dirCode = column[String]("DIRECTORATE_CODE", O.PrimaryKey) def name = column[String]("NAME") def * = dirCode ~ name &lt;&gt; (Directorate, Directorate.unapply _) } case class ServiceArea(areaCode: String, dirCode: String, name: String) object ServiceAreas extends Table[ServiceArea]("SERVICE_AREAS") { def areaCode = column[String]("AREAE_CODE", O.PrimaryKey) def dirCode = column[String]("DIRECTORATE_CODE") def name = column[String]("NAME") def directorate = foreignKey("DIR_FK", dirCode, Directorates)(_.dirCode) def * = areaCode ~ dirCode ~ name &lt;&gt; (ServiceArea, ServiceArea.unapply _) } </code></pre> <p>To make the Directorate case class useful in my Play application form I am trying to redefine the Directorate case class to have a <em>Seq</em> of ServiceAreas that are related to that Directorate. </p> <pre><code>case class Directorate(dirCode: String, name: String, serviceAreas: Seq[ServiceArea]) </code></pre> <p>My problem is now with the Directorate table projection. I have attempted to create a method in Directorates:</p> <pre><code>def serviceAreas = (for { a &lt;- ServiceAreas if (a.dirCode === dirCode) } yield (a)).list map { case t: ServiceArea =&gt; t } </code></pre> <p>so that I can try something like</p> <pre><code>def * = dirCode ~ name ~ serviceAreas &lt;&gt; (Directorate, Directorate.unapply _) </code></pre> <p>but this cannot not work as serviceAreas only goes one way.</p> <p>It seems reasonable to me that for the Directorate case class to be a useful domain object that it should be able contain the related ServiceAreas. </p> <p>I'm wondering how I should traverse the inverse relationship so that Directorate table projection will work. </p>
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