Abstract

Diagrammatic Query Tool (DQT) is a visual data query and presentation interface that helps better exploit and understand large, complex collections of data. This thesis describes the design and implementation of the graphical user interface of DQT with focus on blob support for query construction, blob support for result visualization, automatic translation of query results into DOT format, and presentation of query results with clarity. The implementation of Blobs enables DQT to support the full representative capability of hygraphs and the complete set of Graphlog. With Blob support, users can generalize collections of relationships between one entity and one set of related entities, which makes the construction of queries and visualization of query results more clear, and therefore enables the users' to recognize and discover interesting patterns more easily and intuitively. Graphviz is used to layout query results. Query results must be in the DOT format for Graphviz to produce layouts. Automatic translation of query results into DOT-format graphs has been implemented. This work makes DQT usable by users who do not have knowledge of TGL and DOT. Clarity of result layout and presentation has been achieved by assigning layout properties at the schema level, providing a legend graph for the query result graph and ranking objects in the result graphs.