Question

If I have a class called “car” and this car class uses a SQL query to fill properties like ID, Name, Type, Model, Engine, and Size. How can I populate an asp:formview with that data?

I tried this:

Private currentCar As car        
fvCarview.DataSource = currentCar 
fvCarview.DataBind()

but I keep on getting this error:

Data source is an invalid type.  It must be either an IListSource, IEnumerable, or IDataSource.

Any help would be appreciated!

Thanks

Answer 1

An easy way would be to use a List(Of Car) with a single car in it or a single IEnumerable(Car) via carList.Where(Function(c) c.ID = carID). You could also use a SqlDataAdapter to fill a DataTable and table.Where(Function(r) r.Field(Of Int32)("ID") = carID). Or just select the single car from database which is also the most efficiant way when you don’t need the complete list anyway:

DataTable:

Private Sub fillFormView(carID As Int32)
    Using con = New SqlConnection(My.Settings.SqlConnection)
        Using da = New SqlDataAdapter("SELECT ID, Name, Type, Model, Engine, Size FROM TCAR WHERE ID=@ID", con)
            da.SelectCommand.Parameters.AddWithValue("@ID", carID)
            Dim table = New DataTable
            da.Fill(table)
            fvCarview.DataSource = table
            fvCarview.DataBind()
        End Using
    End Using
End Sub

Here’s your custom Car-Class approach with a single car in a List(Of Car):

Class Car
    Public Property ID As Int32
    Public Property Name As String
    Public Property Type As String
    Public Property Model As String
    Public Property Engine As String
    Public Property Size As Double
End Class

Private Sub fillFormView(carID As Int32)
    Using con = New SqlConnection(My.Settings.SqlConnection)
        Using cmd = New SqlCommand("SELECT ID, Name, Type, Model, Engine, Size FROM TCAR WHERE ID=@ID", con)
            cmd.Parameters.AddWithValue("@ID", carID)
            con.Open()
            Using rd = cmd.ExecuteReader()
                rd.Read()
                Dim carList = New List(Of Car)
                Dim car = New Car()
                car.ID = rd.GetInt32(0)
                car.Name = rd.GetString(1)
                car.Type = rd.GetString(2)
                car.Model = rd.GetString(3)
                car.Engine = rd.GetString(4)
                car.Size = rd.GetDouble(5)
                carList.Add(car)
                fvCarview.DataSource = carList
                fvCarview.DataBind()
            End Using
        End Using
    End Using
End Sub