If your purpose is limited to showing the image in the picturebox you don't need any path, you only need to create one image instance with the data retrieved from the database and assign it to the picturebox's Image property.
byte[] ImageData = <the image="" bytes="">
using (MemoryStream Stream = new MemoryStream( ImageData ))
{
pictureBox1.Image = Image.FromStream( Stream );
} </the>
V.Lorz