A method and system for querying data sources. The query system provides a query definition for defining queries in a uniform manner. The query definition includes a query specification, a data source identifier, and optionally, one or more results transforms. The query definition may be stored as a data structure on computer-readable media, such as a CD-ROM. The query specification includes query text and parameters. The query text specifies the query expression that is to be applied to the identified data source to generate the results. The parameters specify portions of the query text that can be changed by a user before a query is executed.