Abstract: A method, system and article of manufacture for two phase intermediate query security using access control. A networked client-server computer system having a plurality of users of the client-server system and including software performing database queries via a DBMS for users of the system implements the method. The method includes receiving a query string from one of the users by the client system, the query string including references to database objects. The received query string is transformed by the client system to an intermediate query string, and a first phase query security is performed by the client system including identifying the referenced database objects and inserting a security marker into the intermediate query string for each respective identified database object, and sending the intermediate query string to the server system.