Synchronization Method. Object / Relational Mapping Tools

With the constantly development of evolution, Software has to keep varying during its lifecycle, so that it can meet the needs of users' requirements, the runnable environment's requirements and so on. For the software which uses ORM(object/relationaI mapping) as its persistent technology, if the object model and relational model can not get the synchronized updating in its evolution, it may cause dismatch between the two models, and lead mapping mistakes, in that case the persistent operations may not go on, the data may be lost, the state of the data may obey relative restrictions and otherwise. So, it is quite an important job to synchronize ORM during the process of the software's evolution.This paper mainly researches on the synchronization of ORM. In the paper, the author firstly researches the principles of ORM, and then divides the synchronizd process into two steps: first nonsynchronous points detecting and second nonsynchronous points repair. Then, the author gives out the detail methods of detecting nonsynchronous points according to the mapping strategy. The author also gives out an auto repair strategy which is gone under the users' instructions based on the analysis of the basic way to repair nonsynchronous points. In the strategy, the work of repairing is done by the tool and the developers only need to choose the repair method. In this way, the developers can reduce their load largely and also avoid the sightless of absolutely auto repair.The synchronized methods this paper gives are used in the synchronized tool for Hibernate-ORSyn(ORM Synchronizer). This tool can detect all the nonsynchronous points in Hibernate automaticlly and also can repair the simple nonsynchronous points automatically by the instructing of the users, and at last keep the ORM synchronizd in the evolution of the software. This application shows that this tool has good effect and preferably pratical value.