WHERE IN / NOT IN (LINQ, Entity Framework)

        private void frmMain_Load(object sender, EventArgs e)
        {
            // Create new entities Object
            using (var db = new myDatabaseEntities())
            {
                // Array Country Code
                string[] arrCountryCode = new string[] { "TH","US" };

                // Get data from CUSTOMER
                var ds = (from c in db.CUSTOMER
                          where arrCountryCode.Contains(c.COUNTRY_CODE)
                          select c).ToList();

                // if found item rows
                if (ds.Count() > 0)
                {
                    this.myDataGridView.DataSource = ds;
                }
            }
        }

    Private Sub frmMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Create new entities Object
        Using db = New myDatabaseEntities()
            ' Array Country Code
            Dim arrCountryCode As String() = New String() {"TH", "US"}

            ' Get data from CUSTOMER
            Dim ds = (From c In db.CUSTOMER Where arrCountryCode.Contains(c.COUNTRY_CODE)
                   Select c).ToList()

            ' if found item rows
            If ds.Count() > 0 Then
                Me.myDataGridView.DataSource = ds
            End If
        End Using
    End Sub

        private void frmMain_Load(object sender, EventArgs e)
        {
            // Create new entities Object
            using (var db = new myDatabaseEntities())
            {

                // Get COUNTRY
                var country = (from c in db.COUNTRY
                               where c.COUNTRY_CODE == "US" || c.COUNTRY_CODE == "TH" 
                               select c.COUNTRY_CODE).Distinct();

                // Get data from CUSTOMER
                var customer = (from c in db.CUSTOMER
                                where country.Contains(c.COUNTRY_CODE)
                          select c).ToList();

                // if found item rows
                if (customer.Count() > 0)
                {
                    this.myDataGridView.DataSource = customer;
                }

            }
        }

    Private Sub frmMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Create new entities Object
        Using db = New myDatabaseEntities()

            ' Get COUNTRY
            Dim country = (From c In db.COUNTRY
                           Where c.COUNTRY_CODE = "US" Or c.COUNTRY_CODE = "TH"
                           Select c.COUNTRY_CODE).Distinct()

            ' Get data from CUSTOMER
            Dim customer = (From c In db.CUSTOMER
                            Where country.Contains(c.COUNTRY_CODE)
                            Select c).ToList()

            ' if found item rows
            If customer.Count() > 0 Then
                Me.myDataGridView.DataSource = customer
            End If
        End Using
    End Sub

where !country.Contains(c.COUNTRY_CODE)

where Not country.Contains(c.COUNTRY_CODE)