Get (Retrieve) Distinct Records from multiple tables using LinQ in ASP.Net

Hi nauna,

Check this sample now take its reference and correct your code.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

HTML

<asp:GridView runat="server" ID="gvCustomers">
</asp:GridView>

Namespaces

C#

using System.Linq;
using CustomerModel;

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        using (NorthwindEntities entities = new NorthwindEntities())
        {
            var result = (from customer in entities.Customers
                            select new
                            {
                                id = customer.CustomerID,
                                name = customer.ContactName,
                                country = customer.Country
                            });
            var result1 = (from customer in entities.Customers
                            select new
                            {
                                id = customer.CustomerID,
                                name = customer.ContactName,
                                country = customer.Country
                            });
            foreach (var res1 in result1)
            {
                // Checking if id already exist or not.
                if (result.Where(x => x.id == res1.id).Count() < 0)
                {
                    // Add if not exist.
                    result.ToList().Add(new { id = res1.id, name = res1.name, country = res1.country });
                }
            }
            gvCustomers.DataSource = result;
            gvCustomers.DataBind();
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Using entities As NorthwindEntities = New NorthwindEntities()
            Dim result = (From customer In entities.Customers Select New With {Key
                .id = customer.CustomerID, Key
                .name = customer.ContactName, Key
                .country = customer.Country
            })
            Dim result1 = (From customer In entities.Customers Select New With {Key
                .id = customer.CustomerID, Key
                .name = customer.ContactName, Key
                .country = customer.Country
            })

            For Each res1 In result1
                If result.Where(Function(x) x.id = res1.id).Count() < 0 Then
                    result.ToList().Add(New With {Key
                        .id = res1.id, Key
                        .name = res1.name, Key
                        .country = res1.country
                    })
                End If
            Next
            gvCustomers.DataSource = result
            gvCustomers.DataBind()
        End Using
    End If
End Sub