Class Queries

    Public Shared CustomersByCity As  _
        Func(Of Northwnd, String, IQueryable(Of Customer)) = _
            CompiledQuery.Compile(Function(db As Northwnd, _
    city As String) _
        From c In db.Customers Where c.City = city Select c)

    Public Shared CustomersById As  _
        Func(Of Northwnd, String, IQueryable(Of Customer)) = _
            CompiledQuery.Compile(Function(db As Northwnd, _
    id As String) _
        db.Customers.Where(Function(c) c.CustomerID = id))

End Class

public static Func<Northwnd, string, IQueryable<Customer>>
    CustomersByCity =
        CompiledQuery.Compile((Northwnd db, string city) =>
            from c in db.Customers where c.City == city select c);

public static Func<Northwnd, string, IQueryable<Customer>>
    CustomersById = CompiledQuery.Compile((Northwnd db,
    string id) => db.Customers.Where(c => c.CustomerID == id));

' The following example invokes such a compiled query in the main
' program
Public Function GetCustomersByCity(ByVal city As String) As  _
    IEnumerable(Of Customer)

    Dim myDb = GetNorthwind()
    Return Queries.CustomersByCity(myDb, city)
End Function

// The following example invokes such a compiled query in the main
// program.

public IEnumerable<Customer> GetCustomersByCity(string city)
{
    var myDb = GetNorthwind();
    return Queries.CustomersByCity(myDb, city);
}

Class SimpleCustomer
    Private _ContactName As String
    Public Property ContactName() As String
        Get
            Return _ContactName
        End Get
        Set(ByVal value As String)
            _ContactName = value
        End Set
    End Property
End Class

Class Queries2
    Public Shared CustomersByCity As Func(Of Northwnd, String, IEnumerable(Of SimpleCustomer)) = _
        CompiledQuery.Compile(Of Northwnd, String, IEnumerable(Of SimpleCustomer))( _
        Function(db As Northwnd, city As String) _
        From c In db.Customers _
        Where c.City = city _
        Select New SimpleCustomer With {.ContactName = c.ContactName})
End Class

class SimpleCustomer
{
    public string ContactName { get; set; }
}

class Queries2
{
    public static Func<Northwnd, string, IEnumerable<SimpleCustomer>> CustomersByCity =
        CompiledQuery.Compile<Northwnd, string, IEnumerable<SimpleCustomer>>(
        (Northwnd db, string city) =>
        from c in db.Customers
        where c.City == city
        select new SimpleCustomer { ContactName = c.ContactName });
}