Database system, computer program and advertisement presentation method in database system

摘要

A database system comprising: a database storing a plurality of types of information; a storage storing element associated information in which a plurality of elements included in said plurality of types of information are associated with each other and element-advertisement associated information in which advertising information is associated with a combination of two or more elements included in the plurality of elements; and a presentation device visibly presenting the advertising information by referring to the element-advertisement associated information when information entered by a user corresponds to the combination of two or more elements.