title: Mapping Fragments Entity Framework Error
body: <p>I'm developing an ASP.NET MVC4 application (database first approach), right now I updated the model from database and then after that I got this error:</p>
  
  <blockquote>
    <p>Problem in mapping fragments starting at line 1106:Potential runtime violation of table Trn_BenchProficiency's keys (Trn_BenchProficiency.BenchNumber): Columns (Trn_BenchProficiency.BenchNumber) are mapped to EntitySet Trn_BenchProficiency's properties (Trn_BenchProficiency.BenchNumber) on the conceptual side but they do not form the EntitySet's key properties (Trn_BenchProficiency.AssessedDate, Trn_BenchProficiency.BenchNumber, Trn_BenchProficiency.Proficiency, Trn_BenchProficiency.SkillAllignmentID, Trn_BenchProficiency.SkillID).</p>
  </blockquote>
  
  <p>When I double click the error visual studio displayed this:</p>
  
  <p><img src="https://i.stack.imgur.com/qcxJS.png" alt="enter image description here"></p>
  
  <p>Kindly help me, what is the problem with this? I really cant find the error.</p>