1. A computer-implemented method of controlling access to data in a database, comprising: registering a plurality of transformation techniques for a column of a table in said database; computing a query, said query referencing said column; wherein computing said query comprises: selecting a transformation technique from said plurality of transformation techniques; and based on the selected transformation technique, transforming values in said column to generate transformed values to use as the values in said column in lieu of the actual values stored in said column.