anchor.diff:    UNIQUE KEY `id` (`id`),
     KEY `FK_jobhistory_user` (`user`),
     KEY `FK_jobhistory_study` (`study`)
  --- , CONSTRAINT `FK_jobhistory_user` FOREIGN KEY (`user`) REFERENCES `users` (`email`),
  ---  CONSTRAINT `jobhistory_ibfk_3` FOREIGN KEY (`study`) REFERENCES `study` (`name`) ON DELETE CASCADE
   ) ENGINE=NDBCLUSTER DEFAULT CHARSET=latin1;
   /*!40101 SET character_set_client = @saved_cs_client */;
   
  
positive.code:   `added_by` varchar(255) NOT NULL,
    `team_role` enum('Master','Researcher','Guest') NOT NULL,
    PRIMARY KEY (`studyname`,`username`)
  -- ,  CONSTRAINT `FK_study_group_members_studyname` FOREIGN KEY (`studyname`) REFERENCES `study` (`name`)
  ) ENGINE=NDBCLUSTER DEFAULT CHARSET=latin1;
  /*!40101 SET character_set_client = @saved_cs_client */;
  
  
negative.code:   PRIMARY KEY (`name`),
    UNIQUE KEY `name` (`name`),
    KEY `fk_study_users` (`username`)
  ) ENGINE=NDBCLUSTER DEFAULT CHARSET=latin1;
  /*!40101 SET character_set_client = @saved_cs_client */;
  
  