Excerpt from ".NET Classic Example Duwamish 7" (Hao Gang)
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In duwamish7, the problem of business data is resolved by the business entity layer. The business entity layer contains a data set for passing information between each interlayer. Depending on the results of demand analysis, each business entity will model specific information in the database and select different business entities in the appropriate manner. The construction of the business entity layer is the foundation of the application. Except for the SystemFramework project, other layers are used to use the business entity layer.
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Develop applications related to data access by use .NET technology, you must use ADO.NET. ADO.NET is a solution for data access in .NET technology. No techniques related to database access are all from ADO.NET. One of the ADO.NET design goals is to provide advanced support for disconnect N-layer programming environments, using disconnect dataset this concept has become the focus of the programming model. The N layer programming ADO.NET solution is DataSet.
In Duwamish7, DataAdapter and DataSet are used in DataAdapter and DataSet. It should be noted that the business entity is subcatenified to the DataSet as a data carrier, which is to use the type of DataSet to perform data transfer between the layers. ...
The business appearance layer provides the web layer to process the account, category browsing, and books. The business appearance layer is used as an isolation layer that isolates the user interface to the implementation of various business functions. In addition to the low-level systems and support functions, all calls to the database server are made through this data set. The functionality of the business rules is to complete the implementation of various business rules and logic. ... Usually, the business appearance layer calls the business rule layer, and then calls the data access layer through the business appearance layer to complete the interaction with the database. Of course, the business appearance layer can also directly call the data access layer to complete the interaction with the database.
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