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This article mainly explains "what is the use of the ADO.NET model". The content of the explanation is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "what is the use of the ADO.NET model"?

Microsoft recently launched the ADO.NET model, which covers all the functions of previous versions of VS, and the keyboard shortcuts are basically complete, which will not be much different from the upcoming RTM version.

1. If an application only processes Employees information, we must standardize logical data relationships. In this way, we have to pay attention to the relationship between the database table and the table (for example, the employee's contact information and name are in different tables), and we need to artificially do an inline cross-query between the two tables to get the correct data.

two。 The application here only deals with full-time employees (SalariedFlag=1), and ideally, we should not see other types of employee information. In fact, however, all employee information is in a database table, and they are distinguished by a "SalariedFlag" field. The ADO.NET model means that we need to focus on how to distinguish between different types of employees. Ideally, if we only need to deal with a subset of data, the system only needs to render that subset of data. Developers should be able to declare which is the required subset of data.

To sum up, first of all, the relational data model does not directly match the actual data model of the application. Secondly, the relational data model can not meet the actual needs of the application, for example, the application also needs some non-functional requirements, including operations, data ownership relationships, performance and security.

To solve the above problem, ADO.NET introduces Entity Framework, which includes the data model and some design-time and run-time services. Through the higher abstraction layer provided by Entity Framework, the ADO.NET model enables the application's data model to interact directly with the relational data model of the database.

The three entity types, the ADO.NET model is SalesPerson,SalesOrder and StoreSalesOrder. Where StoreSalesOrder inherits from SalesOrder.

One relationship: the relationship between SalesOrder and SalesPerson.

Two entity sets (entity-sets): SalesOrders and SalesPeople. Entity set SalesOrders has two entity types, SalesOrder and StoreSalesOrder.

Take a look at the model view above that is closer to the application requirements. In the ADO.NET model, the information of SalesPerson is no longer distributed in different data tables, and there are no master and slave keys.

Thank you for your reading, the above is the content of "what is the use of the ADO.NET model". After the study of this article, I believe you have a deeper understanding of the use of the ADO.NET model, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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