(System development environment: Windows Myeclipse (server side) Eclipse (mobile client) MySQL database system client and server side architecture technology: interface layer, business logic layer, data layer 3-layer separation technology, MVC design idea! Data communication format between server and client: XML format (about transmission of query record set) and json format (about transmission of single object information) The system implements common CRUD operations such as string, integer, decimal, date type, and image type, and implements foreign key correlation between objects!)