title: hibernate does not recognize an already defined constraint in database
body: <p>I mapped a relationship at the database level, the name of the relationship is <strong>FK_CLASSIFICATION_FRUITS</strong> defined using sql server relationship mapping at the db level. 
  In my Java application, I have an entity mapping in Fruits class to sit on the already defined relationship shown below:</p>
  
  <pre><code>@ManyToOne
      @JoinColumn(name = "CLASSIFICATION_FK", referencedColumnName = "id")
      private Classification clasiFk;
  </code></pre>
  
  <p>The above entity mapping is to establish a relationship between Classification and Fruits and this has already been defined in the database level.</p>
  
  <p>When I try to run my application, I get this error prompt</p>
  
  <pre><code>     ... 90 more
  Caused by: org.hibernate.tool.schema.spi.SchemaManagementException: Unable to ex
  ecute schema management to JDBC target [alter table [FRUITS] add
   constraint FKdctshrn0ebh90up9sh5125nbb foreign key ([CLASSIFICATION_FK]) references
   [CLASSIFICATION]]
  </code></pre>
  
  <p>more of the stacktrace</p>
  
  <pre><code>    ... 88 more
  Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The ALTER TABLE stat
  ement conflicted with the FOREIGN KEY constraint "FKdctshrn0ebh90up9sh5125nbb ".
  The conflict occurred in database "cyz", table "dbo.CLASSIFICATION", column '
  ID'.
          at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError
  (SQLServerException.java:232)
          at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(SQLServ
  erStatement.java:1672)
          at com.microsoft.sqlserver.jdbc.SQLServerStatement.doExecuteStatement(SQ
  LServerStatement.java:903)
          at com.microsoft.sqlserver.jdbc.SQLServerStatement$StmtExecCmd.doExecute
  (SQLServerStatement.java:796)
          at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:7535)
          at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLSe
  rverConnection.java:2438)
          at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(SQLSer
  verStatement.java:208)
          at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(SQLS
  erverStatement.java:183)
          at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeUpdate(SQLServ
  erStatement.java:721)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
  java:62)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
  sorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:498)
          at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(Sta
  tementFacade.java:114)
          at com.sun.proxy.$Proxy113.executeUpdate(Unknown Source)
          at org.hibernate.tool.schema.internal.TargetDatabaseImpl.accept(TargetDa
  tabaseImpl.java:56)
          ... 98 more
  </code></pre>
  
  <p>The above is because, it is not recognizing the already defined constraint</p>
  
  <p>Please how can I inform hibernate that the relationship has already been defined in db</p>