Abstract: A graphical SQL query generator and query operators are disclosed. The query tool embeds matrix objects that are used for building and transforming SQL based queries, views, data cubes and other relations including “virtual” or calculated relations. The matrix objects trace the structure of a relation to its source data and thereby make the structure of complex multilayered database queries transparent to the end-user. The methods are especially useful in data warehousing where the buildup of fact tables in star or other schemas needs to be transparent to the user. Thus, a system is disclosed that is able to quickly reveal how data warehousing schemas and relations in SQL and similar relational type databases evolve from source data and each other into more complicated structures. It supports the creation and maintenance of complex database structures such as scientific studies and other decision support structures as well as simplifying ad-hoc querying of SQL databases.