| 摘要 |
<p>A framework is provided for developing a data access application for use in various environments. When a data operation is performed on a middle tier server in a two-tier environment, the operation and its effects are communicated to the client so that the operation and effects may be recreated there. In a three-tier environment an event manager operating on a middle tier server captures the effects of operations for transmission to a client. A client cache stores a limited amount of data for a data operation and receives the effects of middle tier operations. The granularity of communications between a client and a server may be at the database row or record level rather than at the level of individual fields or attributes. Lightweight proxies allow a client to call a method implemented on a middle tier server without the client including all the programming logic needed to replicate the effects of the call.</p> |
