International Journal of Computing Science and Information Technology (IJCSIT)
With the development of computer network and database, traditional database has been increasing unable to meet the needs of data sharing and interoperability. Meanwhile, it is impossible to abandon all the existing database systems; therefore, the research of simultaneously accessing and processing data from a number of databases has become an inevitable trend. For the Health care information system it's not the issue to retrieve the information from their own databases. But when the authors want the information other than the own databases, then it's an issue to get that information to their system.