Application of database technology in packaging container CAD (Part 2)
2.2 application of packaging database
in order to facilitate the management of database and the information of application program accessing database, Dao is used as the programming interface of application program accessing database in vc++ environment. In the CAD system of packaging containers, the packaging containers are mainly 2. Ball screws: the currently used screws of electronic universal experimental machine include ball screws and trapezoidal screws. The national standards for parameter and other parameter selection are established in the form of MDB through access. In order to improve the efficiency and operability of the software. Packaging CAD system must have friendly human-computer interaction function. For some places that need human intervention, the program should be able to prompt other users, allowing designers to conduct human intervention design. At the same time, the interface between the application software should also be considered. Dao technology completely solves the problems of human-computer interaction and database interface. The user selects the series, type and corresponding model of packaging containers through the list box of the main interface, and then queries the corresponding main parameters through the parameter table. Since China's electric vehicles need more customized materials, according to the main parameters (such as length, volume) and other corresponding parameters of the model selected by the user, And optimize them and output the final parameters to the corresponding part of the parameter design property page of the parameter interface (see Figure 2)
Dao related classes in MFC: cdaodatabase, cdaodatareord view, cdaoreordaset. Cdaodatabase provides a connection interface with the database, through which users can operate the database. After the user selects the packaging container type through the main interface, the corresponding fields in the main parameter table are associated with the member variables of the cdaorecordaset derived class through RFX. The member variable cdaodatareordview class of the cdaorecordaset derived class establishes an association through DDX. At present, cdaodatareordview can display the records in the database through controls, thus establishing the connection between the main dialog box and the database. The auxiliary parameters of the packaging container select the corresponding values in the corresponding database tables according to the selected main parameters. The development process of Dao program in MFC is as follows:
in the packaging container CAD system, information exists in the form of data, and any operation done to the system involves the query, modification, deletion and other operations of data
3 parameterized rapid design of packaging containers
see circle 3, develop parameterized two-dimensional and three-dimensional of standard packaging containers in combination with the database
source: Packaging Engineering Chen Shaowei, Xu Dahua, Yang Tao, Tianjin Business School
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