In this article I will explain with an example, how to get Output parameter from Stored Procedure using Entity Framework in Windows Forms (WinForms) Application using C# and VB.Net.
 
 

Database

I have made use of the following table Customers with the schema as follows.
Get Output Parameter from Stored Procedure using Entity Framework in C# and VB.Net
 
Note: You can download the database table SQL by clicking the download link below.
          Download SQL file
 
 

Stored Procedure

The following Stored Procedure will be used to Insert data into the SQL Server database table.
This Stored Procedure accepts following parameters which are used to insert the records:
Name – This is an INPUT Parameter to pass the Name of the Customer.
Country – This is an INPUT Parameter to pass the Country of the Customer.
CustomerId – This is an OUTPUT Parameter to get last inserted CustomerId.
Note: Output Parameter is identified by the keyword OUTPUT.
 
CREATE PROCEDURE [Customers_InsertCustomer_Output]
      @Name VARCHAR(100),
      @Country VARCHAR(50),
      @CustomerId INT OUTPUT
AS
BEGIN
      INSERT INTO [Customers]
                 ([Name]
                 ,[Country])
      VALUES
                 (@Name
                 ,@Country)
 
      SELECT @CustomerId =SCOPE_IDENTITY()
END
 
 

Entity Framework Model

Once the Entity Framework is configured and connected to the database table, the Model will look as shown below.
Note: For beginners in Windows Forms and Entity Framework, please refer my article Entity Framework Database First Approach in Windows Forms using C# and VB.Net. It covers all the information needed for connecting and configuring Entity Framework.
 
Get Output Parameter from Stored Procedure using Entity Framework in C# and VB.Net
 
Following Stored Procedure is imported as Function.
Get Output Parameter from Stored Procedure using Entity Framework in C# and VB.Net
 
Note: You will notice that None option is selected, because the Stored Procedure does not return any value.
 
 

Form Design

The following Form consists of:
Label – For labelling controls.
TextBox – For capturing Name to be inserted.
ComboBox – For capturing Country Name to be inserted.
Button – For inserting records.
The Button has been assigned with a Click event handler.
Get Output Parameter from Stored Procedure using Entity Framework in C# and VB.Net
 
 

Namespace

You will need to import the following namespace.
C#
using System.Data.Objects;
 
VB.Net
Imports System.Data.Objects
 
 

Populating ComboBox with Country names

Inside the Form Load event handler, the ComboBox items are added.
 
C#
private void Form1_Load(object sender, EventArgs e)
{
    cbCountries.Items.Add("United States");
    cbCountries.Items.Add("India");
    cbCountries.Items.Add("France");
    cbCountries.Items.Add("Russia");
}
 
VB.Net
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    cbCountries.Items.Add("United States")
    cbCountries.Items.Add("India")
    cbCountries.Items.Add("France")
    cbCountries.Items.Add("Russia")
End Sub
 
 

Getting Output Parameter from Stored Procedure using Entity Framework

When Insert button is clicked, the Name and Country value are fetched from their respective fields.
An object of AjaxSamplesEntities is created and ObjectParameter class for CustomerId is initiated.
After that, the Stored Procedure is called using Entity Framework and Name, Country and an ObjectParameter i.e. CustomerId are passed as parameters.
Finally, the inserted CustomerId is fetched from the ObjectParameter value and the TextBox and ComboBox value is set to empty and CustomerId is displayed in MessageBox.
C#
private void OnInsert(object sender, EventArgs e)
{
    string name = txtName.Text;
    string country = cbCountries.SelectedItem.ToString();
    using (AjaxSamplesEntities entities = new AjaxSamplesEntities())
    {
        ObjectParameter param = new ObjectParameter("CustomerId", typeof(int));
        entities.Customers_InsertCustomer_Output(name, country, param);
        string customerId = Convert.ToInt32(param.Value).ToString();
        txtName.Text = string.Empty;
        cbCountries.Text = string.Empty;
        MessageBox.Show("Inserted Customer ID: " + customerId);
    }
}
 
VB.Net
Private Sub OnInsert(ByVal sender As Object, ByVal e As EventArgs) Handles btnInsert.Click
    Dim name As String = txtName.Text
    Dim country As String = cbCountries.SelectedItem.ToString()
    Using entities As AjaxSamplesEntities = New AjaxSamplesEntities()
        Dim param As ObjectParameter = New ObjectParameter("CustomerId", GetType(Integer))
        entities.Customers_InsertCustomer_Output(name, country, param)
        Dim customerId As String = Convert.ToInt32(param.Value).ToString()
        txtName.Text = String.Empty
        cbCountries.Text = String.Empty
        MessageBox.Show("Inserted Customer ID: " & customerId)
    End Using
End Sub
 
 

Screenshots

Get Output Parameter from Stored Procedure using Entity Framework in C# and VB.Net
 

Record after Insert in database

Get Output Parameter from Stored Procedure using Entity Framework in C# and VB.Net
 
 

Downloads

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