title: property 'StoreGeneratedPattern' set to 'Computed' are not supported. Use 'Identity' pattern
body: <p>I am using Entity Framework database First approach</p>
  
  <p>I have a table having composite primary key on 
  ID(int ,identity increment),
  HashKey (binary)  auto generated based on multiple columns using sql hashbytes.</p>
  
  <p>Following is EF Column Mapping</p>
  
  <p>ID storeGeneratedPattern="Identity" and 
  hashkey(binary) storeGeneratedPattern="Computed".</p>
  
  <p>When i try to save using  EF save changes method it is throwing below exception.</p>
  
  <p>"Modifications to tables where a primary key column has property 'StoreGeneratedPattern' set to 'Computed' are not supported. Use 'Identity' pattern instead. Key column: 'HashKey'. Table"</p>
  
  <p>I have applied composite primary key on these columns(Id,Hashkey) to make search faster as it contains cluster index. But not sure whether EF supports this.</p>
  
  <p>I have seen below link. But i am not sure about the solution.</p>
  
  <p><a href="https://stackoverflow.com/questions/8152736/property-with-storegeneratedpattern-set-to-identity-is-not-updted-after-savechan">Property with StoreGeneratedPattern set to Identity is not updted after SaveChanges()</a></p>
  
  <p>Can anybody help on this to resolve the issue.</p>