ODP.NET - Retrieving a Single Row of Information Using OracleDataAdapter
In the previous example, we worked with a set of rows in the DataTable object. Now, we shall work with a particular row using the DataTable object. The following code accepts an employee number from the user and gives you the details of that employee:
Sample Code
Imports Oracle.DataAccess.Client
Public Class Form3
Private Sub btnGetEmployee_Click(ByVal sender As
System.Object, ByVal e As System.EventArgs) Handles
btnGetEmployee.Click
'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()
'check if it has any rows
If dt.Rows.Count > 0 Then
'extract the details
Me.txtEname.Text = dt.Rows(0)("ename")
Me.txtSal.Text = dt.Rows(0)("sal")
Me.txtJob.Text = dt.Rows(0)("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
End Sub
End Class
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Once the DataTable object is filled using OracleDataAdapter, we can directly retrieve a particular row using the row index. Once the row is fetched, we extract column values by providing column names for the rows as follows:
Me.txtEname.Text = dt.Rows(0)("ename")
Me.txtSal.Text = dt.Rows(0)("sal")
Me.txtJob.Text = dt.Rows(0)("job")
The output for the above code would look similar to the following figure:
Tutorials 
