Object-based Data Access

Data Object Access Services is one of the most important technologies and the key methods to implement data object Access nowadays. With the rapid increase of software scale and complexity, if the structure of DB Table changes, the application will be compiled again. From a certain extent Data Object Access Services can effectively reduce develop cost, increase develop efficiency and economize software development time. At first, This paper introduces two Access Model for business data——the ORM(Object Relational Mapping) and BOAS(Data Object Access Services), which is based on structured data. It hides the dissimilarity and complexity of various physical databases, and frees the programmers from the troublesome SQL-based operation for accessing database, by providing the uniform object view and auto-fit interfaces. Also, it describes the implementation of the BOAS briefly.The researches of the paper mainly focus on:(1) How to build the Data Object Module, and How to realize the map of physical Module and Data Object Module.(2) The research of SQL Parser, How to split the SQL sentence, split the SQL into Table、Column、Parameter and so on.(3) How to realize dynamic compilation, how to map the parameters and property.(4) Oracle DB Log’s analysis is a way, to analyse DB changes and realize DB’s changes and updated.(5) This data object access way is implemented in a certain military application system. Practice shows that this access way can hide the data source, it can reduce the alteration because the database’s module chance, it improves the data access performance compared to the ADO access way.