Patent ID: 7870120

Claim:
A method for processing a database query by a proxy server, said proxy server stored on a computer readable medium and executed by a processor of a computer system, said method comprising: receiving the query from an application server, wherein the application server is coupled to a computer-readable memory device; determining whether any database table specified in the query comprises a data isolation field pertaining to a group, wherein a value of the data isolation field identifies a subgroup of the group; if said determining determines that no table specified in the query comprises the data isolation field then performing database server steps of forwarding the query to a database server which is coupled to a database comprising tables having the data isolation field, receiving a response to the query from the database server, and forwarding the response to the application server and into storage within the computer-readable memory device, but if said determining determines that at least one table specified in the query comprises the data isolation field then ascertaining whether the query includes a Where-type clause comprising the data isolation field: if said ascertaining ascertains that the query includes a Where-Type clause comprising the data isolation field then performing the database server steps, but if said ascertaining ascertains that the query does not include a Where-Type clause comprising the data isolation field then performing error steps comprising returning an error code and/or empty dataset to the application server and recording in the computer-readable memory device that a query error has occurred, wherein the receiving step, the determining step, the ascertaining step the database server steps, and the error steps are performed by the proxy server, wherein the database is a relational database, wherein a first database table specified in the query is a secondary table comprising a foreign key that links to a primary table in the database, wherein the primary table has a column consisting of the data isolation field, wherein the secondary table does not have a column consisting of the data isolation field, and wherein the secondary table comprises the data isolation field through its linkage to the primary table via the foreign key.