Described is answering online web queries from a structured data store, such as a products database. An online web search query is modified into an evaluation expression for accessing a structured data store (e.g., a database, XML file, a flat table) to find search results. A query is matched to a pattern, which is used to generate the expression, as well as determine to which structured data store the query is routed. Tokens (e.g., words) in the query are processed against a dictionary of token classes (sets of tokens) and patterns (sets of token classes) to annotate the query to map the query to the matching pattern. A translation process generates the expression based on translation hints that correspond to the matching pattern. Also described is offline mining of query logs to generate the dictionaries.