Embodiments of the present invention disclose a method, computer program product, and system for searching a database using a user entered search query. A search query for a database is received by the computer and the computer applies condition-action rules based on natural language processing rules to identify one or more phrases within the search query that is associated an entity identifier. The computer further identifies any taxonomy variants that have been established for the identified phrases. The computer creates a search string that includes search query and the entity identifiers. The database search is conducted by the computer and the results are displayed for the user.