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This article shows you how to use ADO.NET connection database, the content is concise and easy to understand, it can definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

If the command we execute with the Command object is a Select description that returns data, the Command object automatically generates a DataReader object. DataReader is a good friend for us to write ASP.NET pages, because we often take out the data from the data source and display it to the user, so we can use the DataReader object. We can receive it by passing in a variable of type DataReader when executing the Execute method.

The DataReader object simply reads only one record at a time, and can only be read-only, so it is very efficient and can reduce the network load. Because Command objects automatically generate DataReader objects, we just need to declare a variable referring to the DataReader object to receive it, and we don't need to use the New operator to generate it; another thing to note is that DataReader objects can only be used with Command objects, and the Connection object remains online during operation.

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After we get the DataReader object generated by the Command object executing the Execute method, we can extract and use the data in the record. DataReader didn't get any data back at first, so we need to use the Read method to get DataReader to read a piece of data first. If the DataReader object successfully gets the data, it returns True, and if no data is obtained, it returns False. In this way, we can use the Do While...Loop loop to get all the data, as shown in the following program:

Dim cmA As ADOCommand= New ADOCommand ("command string", "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source=C:\ Inetpub\ wwwroot\ cr\ ch05\ MyWeb.mdb") Dim drA as ADODataReadercmA.ActiveConnection.Open () cmAcmA.CommandText= "Select * From Members" cmA.Execute (drA) the above is how ADO.NET connects to the database. Have you learned any knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

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