Cross-database Platform Middleware And Applications

Database system is a very important part in computer science. There are more than one heterogeneous database systems in a company or an office, which increase the requirements of transporting application softwares among heterogeneous databases.Transtporting software in heterogeneous databases is also very difficult and complicated because the SQL (Structured Query Language) in an application software is for a special database and cannot be used commonly.lt is necessary to design a middleware between software and database which can shield the differences of SQL operations for heterogeneous databases, and can give an active action in application softwares transporting between two different databases.This paper deeply studies the differences of SQL operations and their influences to an application software, and designs a middleware JUDB which can transport software among heterogeneous databases. It also gives the design and realization of its main modules, such as SQL Parser, RDBT and Adapter. JUDB makes the operations from application softwares to Oracle, DB2, SQLServer, Mysql and Sybase be transparent, and achieves the aim of application softwares transporting between heterogeneous databases. Based on the above middleware research, the paper presents a solution that can transport data in heterogeneous databases using XML, and the inconsistent problem in the data forms among heterogeneous databases can be solved easily.JUDB attains the aim of shielding the operating differences of heterogeneous databases, makes database operations be transparent to application softwares, and completes application softwares transporting among heterogeneous databases.