update images in sqlserver using vb

my db table is tbltest with id(int),name(varchar),lastname(varchar),foto(datatype image)
i can insert data in my database but i don't now to update them
i have store data in my db ,and i will to update them with a button (update)
the code for my insert button is

cmdtabela1 = connetion.CreateCommand
                  cmdtabela1.CommandText = "insert into tbltest values (@name,@lastname,@foto) "

                  cmdtabela1.Parameters.AddWithValue("name", txtname.Text)
                  cmdtabela1.Parameters.AddWithValue("lastname", txtlastname.Text)
                  


                  Dim ms As New MemoryStream()
                  PictureBox1.BackgroundImage.Save(ms, PictureBox1.BackgroundImage.RawFormat)
                  Dim data As Byte() = ms.GetBuffer()
                  Dim p As New SqlParameter("foto", SqlDbType.Image)
                  p.Value = data
                  cmdtabela1.Parameters.Add(p)

now how to update this colums in my database

i have write this code for my update button

connetion = New SqlConnection("my conetion string")
                    connetion.Open()

                    Dim ms As New MemoryStream()
                    PictureBox3.BackgroundImage.Save(ms, PictureBox3.BackgroundImage.RawFormat)
                    Dim data As Byte() = ms.GetBuffer()
                    Dim p As New SqlParameter("Foto", SqlDbType.Image)
                    p.Value = data
                    cmdtabela.Parameters.Add(p)

                    cmdtabela = connetion.CreateCommand
                    cmdtabela.CommandText = "update tbltest set name='" & txtupdatename.Text & "', lastname='" & txtupdatelstname.Text &   where Id='" & Trim(txtid.Text) & "'"

Tags: Visual Basic