ADO.NET Dataset and DataView Components in VB.NET
In this article I will explain about understanding Dataset and DataView Components in ADO.NET.
After discussing data adapters and data connections, you got a pretty good idea of how to take advantage of VS.NET design - time support to develop data bound windows form database applications.
The DataSet and DataView components are two powerful and easy-to-use components of the ADO .NET model. In this section, you'll see how to utilize DataSet and DataView components at design-time. The DataSet and DataView components fall in the disconnected components category, which means you can use these components with or without data providers. These components work in the same way for all data providers, including Sql, OleDb, and Odbc.
Understanding Typed DataSets in Visual studio .NET
There are two types of datasets: typed datasets and untyped datasets. A typed dataset has an XML schema attached to it. The XML schema defines members for a dataset corresponding to database table columns, and you can access data through these columns. Untyped datasets are ones that are created at run- time and don't have a schema attached to them. I'll now show you how can generate typed datasets using a VS .NET wizard.
Generating Typed DataSets Using Data Adapters
You can generate typed datasets by using any of data adapters. You can either generate a dataset by right- clicking on a data adapter and selecting the Generate Dataset menu option or by using the data adapter properties windows. To Generate a Dataset from data adapter's properties window. Choose the Generate Dataset hyperlink, which generates a DataSet object, and the wizard writes the code for you (see figure 4-45).
Figure 4-45. Generating a typed dataset from the Properties windows
This action pops up a dialog box, which generates a dataset. Type your dataset name and click OK (see figure 4-46).
Figure 4-46. Dialog box for generating a dataset
This action adds a dataset (if you check Add This Dataset to the Designer check box) and pops up the dataset properties dialog box (see figure 4-47).
Figure 4-47. A dataset's properties windows showing a typed dataset
Every dataset generated by the IDE creates an XML schema for the dataset. Figure 4-47 providers you with two hyperlinks at the bottom of the dialog: View Schema and DataSet properties. View schema lets you view the DataSet schema, and the DataSet properties hyperlink lets you set the DataSet properties. By following these links you can set the DataSet's column names and other properties (see figure 4-48).
Figure 4-48. Setting Dataset names and additional properties
This action also adds one class inherited from a DataSet and one XML schema (DataSet1.xsd). The class view of the DataSet is a derived class and looks like figure 4-49.
Figure 4-49. A VS.NET- generated typed DataSet class
You can now create an instance of this class instead of creating a DataSet programmatically. This class has a member corresponding to each column of the table to which it's attached:
Dim ds As New MyDataSet()
The beauty of typed datasets is that you can access the data in the columns using MyDataSet object members.
Besides creating a DataSet using the Data Adapter Configuration wizard, there is another good way to do so. I'll discuss this alternate solution in the following article.
Hope this article would have helped you in understanding Dataset and DataView Components in ADO.NET. See my other articles on the website on ADO.NET.