Peter Teuben
University of Maryland, College Park
Dynamic Queries (DQ) is a recently developed querying technique (Shneiderman 1993) which proved to be a good alternative to the often difficult to learn but very general and flexible SQL-type interface to a relational database. The query in DQ is formulated using a number of graphical widgets that represent a column from a table (columns can be numeric as well as textual). Using two sliders a range search can be set for a column, and the resulting view of this multiply OR-ed selection is dynamically viewed in a canvas. The canvas can display simple points, but additional information can optionally be added to these points (color, size, etc.). Once sufficient selections have been made, some implementations of DQ then allow the displayed data to be queried in more detail by e.g. clicking on the point. A number of specific examples of DQ have been discussed in recent years. This paper discusses a generic (ascii-widget) implementation where the input dataset can be an arbitrary table-like dataset. A selection of the viewing coordinates X and Y is made, as well as the columns that can be queried. In addition to the above described features, we also implement a generic (user definable) interactive analysis tool that is dynamically associated with the query. We call this technique Dynamic Dynamic Queries (DDQ).