In recent years, there has been a growing demand for the development of authentication, authorization and accounting (AAA) systems for WLAN networks. In this paper we present a network architecture of SQL database servers especially tailored for AAA functions in large WLAN systems. Proposed database network architecture is vendor independent in sense that can be deployed with different AAA server implementations. WLAN management information database for AAA purposes is center of a WLAN network management system providing control of parameters such as: authentication and authorization of users, deletion or creation of users information, storage of accounting information which can be used for billing. Detailed database structure of each SQL database server in proposed centralized-distributed AAA database network architecture is described. Working principles of network database system for WLAN AAA purposes are based on MySQL master/slave chain replication. Proposed network architecture of SQL databases offers high level of reliability, availability and scalability.