Visual SQL ? High-Quality ER-Based Query Treatment

Query formulation is still a difficult task whenever a database schema is large or complex. The user has to entirely understand the schema before a correct and complete formulation of the query will be found. Furthermore, users may overlook types in the SQL schema that must be used in the query. We show in this paper that visualization led in this case to higher conceptual correctness and conceptual completeness. Visualization is based on Visual SQL. Visual SQL follows the paradigm of entity-relationship representation. At the same time, it has the same expression power as SQL-92. The quality of query formulation is, however, higher.