C# How to Check If Picturebox image is already exist in Database

Question

Below these code I'm trying to validate if my picturebox image is already exist in database. To be more precise, if user try to insert same image it will validate that "Image Already exist"

Here's the error i got :

(The parameterized query '(@Image varbinary(8000))Select COUNT(*) from employee_product wh' expects the parameter '@Image', which was not supplied.')

What i do wrong here ? or Did i forgot something ? I hope someone would be able to help me. Thank you

public partial class ADDProduct : MetroForm
{
    SIMSProduct _view;
    public ADDProduct(SIMSProduct _view)
    {
        InitializeComponent();
        this._view = _view;                 
    }
    DataTable dt = new DataTable();
    byte[] photobyte;
    string date = DateTime.Now.ToString("MMMM-dd-yyyy");
    public void ValidateImage(byte[] image)
    {
        using (var con = SQLConnection.GetConnection())
        {
                using (var select = new SqlCommand("Select COUNT(*) from employee_product where Image= @Image", con))
                {

                select.Parameters.Add("@Image", SqlDbType.VarBinary).Value = photobyte;
                    using (var sda = new SqlDataAdapter(select))
                    {
                        int count = (int)select.ExecuteScalar();
                        if (count > 0)
                        {
                            lbl_image.Show();
                        }
                    }
                }
        }          
    }
 private void btn_add_Click(object sender, EventArgs e)
    {
        _view.ID = txt_id.Text;
        using (var con = SQLConnection.GetConnection())
        {
            if (string.IsNullOrEmpty(cbox_supplier.Text) || string.IsNullOrEmpty(txt_code.Text) || string.IsNullOrEmpty(txt_item.Text) || string.IsNullOrEmpty(txt_quantity.Text) || string.IsNullOrEmpty(txt_cost.Text) || pictureBox1.Image == null )
            {
                CustomNotifcation.Show("Please input the required fields", CustomNotifcation.AlertType.warning);
            }
            else
            {
                ValidateItem.IsValidItem(txt_code, lbl_code);
                ValidateImage(photobyte);
                if (lbl_code.Visible == true)
                {
                    CustomNotifcation.Show("CODE ALREADY EXIST", CustomNotifcation.AlertType.error);
                    lbl_code.Visible = false;
                }
                else if (lbl_image.Visible == true)
                {
                    CustomNotifcation.Show("IMAGE ALREADY EXIST", CustomNotifcation.AlertType.error);
                    lbl_image.Visible = false;
                }
                else
                {
                    using (var select = new SqlCommand("Insert into employee_product (Image, ID, Supplier, Codeitem, Itemdescription, Date, Quantity, Unitcost) Values (@Image,@ID, @Supplier, @Codeitem, @Itemdescription, @Date, @Quantity, @Unitcost)", con))
                    {
                        var ms = new MemoryStream();
                        pictureBox1.Image.Save(ms, pictureBox1.Image.RawFormat);
                        photobyte = ms.GetBuffer();

                        select.Parameters.Add("@Image", SqlDbType.VarBinary).Value = photobyte;
                        select.Parameters.Add("@ID", SqlDbType.VarChar).Value = txt_id.Text;
                        select.Parameters.Add("@Supplier", SqlDbType.VarChar).Value = cbox_supplier.Text;
                        select.Parameters.Add("@Codeitem", SqlDbType.VarChar).Value = txt_code.Text.Trim();
                        select.Parameters.Add("@Itemdescription", SqlDbType.VarChar).Value = txt_item.Text.Trim();
                        select.Parameters.Add("@Date", SqlDbType.VarChar).Value = date;
                        select.Parameters.Add("@Quantity", SqlDbType.Int).Value = txt_quantity.Text.Trim();
                        select.Parameters.Add("@Unitcost", SqlDbType.Int).Value = txt_cost.Text.Trim();
                        select.ExecuteNonQuery();
                        CustomMessage.Show("Message: Item successfully added!", CustomMessage.Messagetype.Success);
                        pictureBox1.Image = null;
                        cbox_supplier.Items.Clear();
                        txt_code.Clear();
                        txt_item.Clear();
                        txt_quantity.Clear();
                        txt_cost.Clear();
                        _view.btn_update.Enabled = false;
                        _view.AddingProduct();
                        this.Close();
                    }
                }                
            }                
        }
    }
    private void pictureBox1_Click(object sender, EventArgs e)
    {
        using (OpenFileDialog ofd = new OpenFileDialog())
        {
            ofd.Filter = "Image Files (*.jpg;*.jpeg;.*.png;)|*.jpg;*.jpeg;.*.png;";
            ofd.FilterIndex = 1;
            ofd.Multiselect = false;
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                pictureBox1.Image = Image.FromFile(ofd.FileName);

            }
        }
    }
 }

Answer 1

You can generate some unique values for a file like hash or check-sum and store it along with byte stream in DB, which can be used to check for whether the file exists or not. Normally these mechanisms are not used for this. This only works if file contents are exactly same. Even slightest of variation will be failed to identify the match.

You can find hash like string hash:

using(SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider())
{
    hash = Convert.ToBase64String(sha1.ComputeHash(byteArray));
}

OR alternatively you can decide to store some alternate information like we normally do. Like file name or user based validations to check whether the file exists.