View Relational Data in a DataGrid

This article explains to you how easy is to read a database and displaying in a grid using DataSet.

 

In this sample example, I have used the access 2000 database, Northwind.mdb. We access the Customers table of the Northwind database and display records in a datagrid control.

 

Starting: Create a Windows Application type project and add a DataGrid control to the form. Leave DataGrid name as DataGrid1.

 

Add Reference to the Namespace

 

First thing you need to do is add a reference to System.Data.OleDb namespace since I will use OldDb data providers. if System.Data namespace is not present, you might want to add this too.

using System.Data.OleDb;

Create OleDbDataAdapter Object

 

Now you create a OleDbDataAdapter object and connect to a database table.

// create a connection string
string connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Northwind.mdb";
OleDbConnection myConnection = new OleDbConnection();
myConnection.ConnectionString = connString;// create a data adapter OleDbDataAdapter da = new OleDbDataAdapter("Select * from Customers", myConnection);

Create a DataSet Object and Fill with the data

 

You use Fill method of OleDbDataAdpater to fill data to a DataSet object.

// create a new dataset
DataSet ds = new DataSet();
// fill dataset
da.Fill(ds, "Customers");// write dataset contents to an xml file by calling WriteXml method

Attach DataSet to DataGrid

 

Now you use DataSource method of DataGrid to attached the DataSet data to the data grid.

// Attach DataSet to DataGrid
dataGrid1.DataSource = ds.DefaultViewManager;

Here is entire source code written on the form load method.

private void Form1_Load(object sender, System.EventArgs e) {
    // create a connection string
    string connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Northwind.mdb";
    OleDbConnection myConnection = new OleDbConnection();
    myConnection.ConnectionString = connString; // create a data adapter OleDbDataAdapter da = new OleDbDataAdapter("Select * from Customers", myConnection);
    // create a new dataset
    DataSet ds = new DataSet();
    // fill dataset
    da.Fill(ds, "Customers"); // write dataset contents to an xml file by calling WriteXml method
    // Attach DataSet to DataGrid
    dataGrid1.DataSource = ds.DefaultViewManager;
}

The output of the program looks like the following figure.