title: Issue with AssociationSet in EF when changing target from .NET 4.0 to 3.5
body: <p>I developed a <strong>Repository</strong> component targeting the <strong>.NET 4 Framework</strong> that uses <strong>EF</strong>. In my EF I use tables already existing in the <strong>Database</strong>. </p>
  
  <p>In the Database I have 4 tables representing <strong>entities</strong> and <strong>3 association tables</strong> (the relationships between the entities are all many-to-many) </p>
  
  <p>However these tables at Database level <strong>do not</strong> have any <strong>relation</strong> between each other. Since I do not have rights to modify the Database, I added the relations directly in the EF. I named them, I specified the navigation properties and then I successfully compiled and tested the project.</p>
  
  <p>Now I have to reference this Repository project from a <strong>Web application</strong> using the <strong>.NET 3.5</strong>. Therefore also the Repository project must reference the .NET 3.5.</p>
  
  <p>I correctly copied the connection string from the Repository project to the <strong>web.config</strong>, I compiled the project and...it gives me a compile error saying that there is</p>
  
  <blockquote>
    <p>"no mapping specified between EntitySet/AssociationSet"</p>
  </blockquote>
  
  <p>and then lists the relationships between tables/entities.</p>
  
  <p>I guess this error is given because there are no associations at Database level. How can I solve this issue without having to rewrite all my code?     </p>