Create a Data Adapter in ADO.NET

This article has been excerpted from book "A Programmer's Guide to ADO.NET in C#".

The first step is to drag and drop an OleDbDataAdapter component from the toolbox's Data tab. As you drop the OleDbDataAdapter on the page. The Data Adapter Configuration Wizard pops up on the screen. You then follow these simple steps: At the generate the SQL Statement page, select the EmployeeID, FirstName, LastName, Title, City, and Address fields from the Employees table, as shown in Figure 7-30.


Figure 7-30. Generating a SQL statement using the Query Builder

The Finish buttons adds a data adapter and a connection object to the project. Now if you view the code of your page using the View Code option, you see the wizard has added an OleDbDataAdapter, an OleDbConnection, and four OleDbCommand variables to your project. The variables look like this:

        protected System.Data.OleDb.OleDbDataAdapter oleDbDataAdapter1;
        protected System.Data.OleDb.OleDbCommand oleDbSelectCommand1;
        protected System.Data.OleDb.OleDbCommand oleDbInsertCommand1;
        protected System.Data.OleDb.OleDbCommand oleDbUpdateCommand1;
        protected System.Data.OleDb.OleDbCommand oleDbDeleteCommand1;
        protected System.Data.OleDb.OleDbConnection oleDbConnection1;

Generating a DataSet from Data Adapter

The next Step is to generate a data a dataset from the data adapter. To generate a dataset from the OleDbDataAdapter, right-click on the OleDbDataAdapter, and click the generate dataset menu option. The option brings up the Generate Dataset page, as shown in figure 7-31. The Default name of the dataset is DataSet1.


Figure 7-31. Generating a dataset using the data adapter's generate Dataset option

This page actually a class called DataSet1, which comes from the DataSet class. This class looks like figure 7-32 in Class View.


Figure 7-32. The Class View representation of the Data Set1 class

This action also adds one DataSet variable, named dataset11, to your project (See Figure 7-33).


Figure 7-33. The data Set11 variable generated by the data adapter

You'll be using this data set11 in your application; it represents a dataset having data from the Employees table (The SQL statement you saw in Figure 7-30).

Creating a DataView and Connecting It With a Data Set

The Next step is to connect the dataset to a data view. To do so, drop a DataView from the toolbox's Data tab onto the page and set its Table property to dataset11.Employee, as shown in Figure 7-34.


Figure 7-34. Setting the Table property of as data view 

Dropping a data view control to the page adds a data view control named as dataView1.

Binding a DataGrid

Now set the data grid control's DataSource property to the data view. I set DataGrid.DataSource property to dataView1, as shown in figure 7-35.


Figure 7-35. Setting the DataGrid's DataSource property

Filling DataSet

You're almost there. Now the only thing you need to do is to call the data adapter's Fill method and fill the dataset, and you're all set. Call the oleDbDataAdapter1.Fill method with dataset11 as the only argument on the Page_Load event and then call the DataGrid1.DataBind method to bind data grid with the data. Lsting 7-5 shows how do to this.

Listing 7-5. The dataSet from DataAdapter

private void Page_Load(object sender, System.EventArgs e)
            // Put user code to Initialize the page here

Now run the project, the output of the project looks like Figure 7-36.


Figure 7-36. Viewing data in a data grid using the design time data binding method

As you can see from the previous discussion, by writing only two lines of code, you've developed a database application.


Hope this article would have helped you in understanding how to Create a Data Adapter in ADO.NET. See other articles on the website also for further reference.

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