title: Laravel-OCI8 ORA-02275: such a referential constraint already exists in the table
body: <p>I've been trying to use migrations for a cross-dbms database. Using entrust and confide packages, I added migrations after them to add a user_statuses table and a reference in users table to user-statuses' ids; but as I define the foreign key I get this: </p>
  
  <pre>
  [Illuminate\Database\QueryException]
  Error Code    : 2275
  Error Message : ORA-02275: such a referential constraint already exists in the table
  Position      : 53
  Statement     : alter table users add constraint users_state_foreign foreign key ( state ) references user_statuses ( id ) (SQL: alter table users add constraint users_state_foreign foreign key ( state ) references user_statuses ( id ))
  
  [yajra\Pdo\Oci8\Exceptions\SqlException]
  Error Code    : 2275
  Error Message : ORA-02275: such a referential constraint already exists in the table
  Position      : 53
  Statement     : alter table users add constraint users_state_foreign foreign key ( state ) peferences user_statuses ( id )
  </pre>
  
  <p>Below are the user_statuses and the alteration migration.
  user_status creation:</p>
  
  <pre><code>Schema::create('user_statuses', function($table){
      // Columns
      $table-&gt;increments('id')-&gt;unsigned();
      $table-&gt;string('name');
  
      // Indexes
  
      // Constraints
  });
  </code></pre>
  
  <p>users alteration:</p>
  
  <pre><code>Schema::table('users',function($table){
      // Columns
      $table-&gt;integer('state')-&gt;unsigned();
      $table-&gt;softDeletes();
  
      // Indexed
  
      // Constraints
      $table-&gt;foreign('state')-&gt;references('id')-&gt;on('user_statuses');
  });
  </code></pre>