1. A computer program product comprising at least one non-transitory computer-readable storage medium storing one or more sequences of instructions, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to generate a query to retrieve a set of stored data records from a data store by performing steps comprising: providing a repository of terminology content, wherein the terminology content includes a plurality of backbone classes that form data structures representing a plurality of high level concepts, wherein the plurality of high level concepts includes a plurality of semantically equivalent concepts stored in one or more of domains of concepts, and wherein the plurality of semantically equivalent concepts are mapped to one another using inter-domain or intra-domain mappings defined in the terminology content; receiving an initial query comprising a set of search criteria comprising a seed concept; generating an equivalence concept query based on at least a subset of the search criteria that includes the seed concept; providing the equivalence concept query to a terminology service which manages the repository of terminology content, wherein the terminology service operates to extract, from the terminology content, a set of concepts that are semantically equivalent to the seed concept using the defined mappings; receiving the set of concepts that are semantically equivalent to the seed concept in response to submitting the equivalence concept query to the terminology service; and generating a structured query language (SQL) query for retrieving a set of structured records from an electronic data record system, wherein the SQL query comprises predicates corresponding to the seed concept and the set of concepts semantically equivalent to the seed concept, and an equality predicate that compares a search criterion attribute value to a value within a structured record to determine they are equal.