ODP.NET - Working with DataTableReader
DataTableReader is complementary to a DataTable object, and is mainly used as a type of Data Reader in the disconnected mode. The following is the modified code:
Sample Code
'create connection to db
Dim cn As New OracleConnection("Data Source=xe; _
User Id=scott;Password=tiger")
Try
Dim SQL As String
'build the SELECT statement
SQL = String.Format("SELECT ename, sal, job FROM emp
WHERE empno={0}", Me.txtEmpno.Text)
'create the DataAdapter object
Dim adp As New OracleDataAdapter(SQL, cn)
'create the offline datatable
Dim dt As New DataTable
'fill the data table with rows
adp.Fill(dt)
'clear up the resources and work offline
adp.Dispose()
Dim dtr As DataTableReader = dt.CreateDataReader
'check if it has any rows
If dtr.HasRows Then
'read the first row
dtr.Read()
'extract the details
Me.txtEname.Text = dtr("ename")
Me.txtSal.Text = dtr("sal")
Me.txtJob.Text = dtr("job")
Else
'display message if no rows found
MessageBox.Show("Not found")
End If
Catch ex As Exception
'display if any error occurs
MessageBox.Show("Error: " & ex.Message)
'close the connection if it is still open
If cn.State = ConnectionState.Open Then
cn.Close()
End If
End Try
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You can observe the highlighted code, which creates a DataTableReader object by calling the CreateDataReader method related to the DataTable object. Once the DataTableReader is created, we can directly retrieve the column values with the specified column names as follows:
Me.txtEname.Text = dtr("ename")
Me.txtSal.Text = dtr("sal")
Me.txtJob.Text = dtr("job")
Tutorials 
