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This article mainly introduces "how to install ADO.NET EF correctly". In daily operation, I believe many people have doubts about how to install ADO.NET EF correctly. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "how to install ADO.NET EF correctly". Next, please follow the editor to study!

Now we see that the ADO.NET EF of this query is the same as the ADO.NET EF effect of the query designed directly with the query view. In fact, all the database operations of ADO.NET EF are made up of SQL language, and Microsoft just adds a more convenient operation wizard ADO.NET EF and visual design on it.

When we create the same ADO.NET EF query directly from the design view and switch the view to the SQL view, you will be surprised to find the same statement in the SQL editor in this view. It seems to be a statement automatically generated by ACCESS. It turns out that ACCESS is also a SQL statement, and then use these statements to operate the database.

Now let's talk about the use of the latter clauses in the SELECT statement. You find that these clauses are adapted by square brackets, which shows that these clauses are optional in the SELECT statement, where the WHERE clause is a row selection declaration clause, which can be used to restrict our selected rows, that is, the records in the table, and these rows can be used as query rows only when the row selection description after WHERE is true, and there can be a variety of constraints in WHERE. These conditions can be joined by logical operators such as "AND".

Astoria is the infrastructure of data services on the Internet developed by Microsoft. ADO.NET EF is based on the REST architecture and helps developers access data only through standard HTTP protocols such as GET,POST,PUT or DELETE. Astoria is built on top of ADO.NET Entity Framework and uses standard data formats such as XML,JSON or RDF for data transfer. Now that CTP is available for download, you need to install ADO.NET Entity Framework and related Tools before using Astoria.

After installing ADO.NET EF,Tools and Astoria CTP, you can use it. First open VS 2008 beta2, set up the Web Application project, and then use the ADO.NET EF wizard to map the tables Customers and Orders in the database (on how to map, which was mentioned in my article ADO.NET Entity Framework Learning (1)).

You can see that the data returned here is in XML format, which can be easily displayed with RIA. There are two items in NorthwindEntities, Customers and Orders, each including an attribute named href, where the value is the access path. If we want to visit all the Customers, add / Customers after the url, and we can see the result

You can also add conditional queries, such as / Customers [City eq London], to get Customer of all cities with London. If you want to query the Orders of a Customer, add / customers [ALFKI] / Orders after url to get all the Orders of ALFKI users:

Astoria is a very useful framework that allows developers to easily program data access ADO.NET EF.

At this point, the study on "how to install ADO.NET EF correctly" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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