Databases
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    <p>System.Data is the "package" that contains everything for working with "Data providers" in .NET. It is true that ADO, is one strategy for working with data, but it is the primary strategy in .NET. </p> <p>ADO is less about specific DB technologies (as it is not necessarily meant to be a database specific technology) and more about data relationships. The terms: Set, Table, Column, Row and Relationship are well understood modeling terms and ADO.NET makes them first class objects in the .NET space.</p> <p>Data providers provide low-level implementation specific details for supporting the core ADO.NET concepts (tables, rows, etc) and are meant to abstract away the direct implementation details of how to connect to a data provider. For instance, you should be able to, with relatively little effort, swap out a Jet Data provider, with a Oracle Data provider, in terms of DataTables, DataRows, and DataColumns (query details aside) such that your code is minimally impacted by the change. Why is this important? Because it means you can work with non-homogenous data sources with similar command semantics (i.e. you can work with excel spreadsheets and MySql dbs in the same app with the same objects). This makes reuse and repurposing very easy and very straight-forward.</p> <p>As a general view you can think of the system this way:</p> <ol> <li>The .NET Data provider is where you get your data from. You will need to import from System.Data each provider that your app uses</li> <li>The ADO.NET classes are the concepts you will be working with Tables, Rows, Columns, etc. These have nothing to do with queries, indexes, etc. Those are provider details</li> <li>Your app should only rarely (I would say never, but there are always exceptions) need to be aware of the Provider and instead focus on consuming and producing DataSets, DataTables, etc.</li> </ol> <p>Hope that helps.</p>
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    1. POIs my overview of .Net Data Providers and ADO.Net correct?
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    1. POIs my overview of .Net Data Providers and ADO.Net correct?
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    1. COThis helps a lot. I wish the MSDN docs were this clear. My background in Java and php made it hard to relate to ADO.Net(DataTable specifically). I totally agree about programming independent of a specific provider. You can do that even without the DataTable and DataSet classes, which as you said are independnet of providers because they are concrete classes in the System.Data namespace. If you hide the "Data provider" implementation behind the interfaces in the System.Data namespace you can change your provider at anytime. Thx for the reply.
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    2. CO@Welzie its true you dont need to use the DataTable and DataSet as the DataReader provides a much easier to understand DB reader semantic, but DataTable (DT) and DataSet (DS) are meant to convey a different meaning than a one-way movement of data. The DT and DS are meant to provide proxy implementations of data usage and give you a disconnected interface to your data provider, such that the DT/DS "act" as the database, and the underlying details are not important to consuming code. I think in practice this is not how the DT and DS are used though, usually they are just containers for data.
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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