Abstract

Diagrammatic Query allows users to compose a query through diagrams in a Graphical User Interface (GUI) environment. Diagrammatic Query has three basic requirements that must be fulfilled: (1) Both the query and query results should be presented graphically. (2) The users should be able to query database intuitively. (3) Queries should not only refer to information that resides at databases, but also to views based on defined queries, defined previously, which are saved in the system. We utilize the logic of Graphlog and CORAL so that users are able to pose queries by drawing nodes, edges and blobs, and probably by specifying which existing views are to be included. This thesis proposes the definition of Transferable Graph Language and the analysis, design, and implementation of the translation system. The transformation and storage format used by our project is specified in Transferable Graph Language (TGL), which uses XML DTD to regulate the program structures. The translation system will be driven by TGL programs transferred from the GUI system. These TGL programs collect node, edge, and blob status and information about how they are related. Also they will inform which existing views will be involved. Then the translation system will analyze these data and translate them to CORAL programs. Next, the translation system will organize calls to CORAL system and collect query results received from the CORAL system. At the end, the translation system will transform the results as TGL result programs and return them to the GUI system for displaying to users.