bar code data and Update/insert

Question

Guys i am new to C# and stuck on below problem

 

1. i am not able to update data as per below code. insert is working normally but not the update. some syntax error which i cant figure out.

 

2. barcode is populated but not able to either insert/ update. gives me error. while if input normal number from my keyboard is gets inserted in database. so why barcode is not getting checked on SELECT command.

private void button1_Click(object sender, EventArgs e)
{
SqlConnection cn = new SqlConnection(global::Inventory_System.Properties.Settings.Default.Database1ConnectionString);
cn.Open();
SqlCommand cmdCount = new SqlCommand("SELECT count(*) from Stock WHERE ProductCode = @ProductCode", cn);
cmdCount.Parameters.AddWithValue("ProductCode", tbstockpc.Text);
int count = (int) cmdCount.ExecuteScalar();
if (count > 0)
{
try
{
int Stprice = 0;
int qty = Convert.ToInt32(tbstockqty.Text);
int puprice = Convert.ToInt32(tbstockpurprice.Text);
Stprice = qty * puprice;
string sql = "Update Stock(ProductCode,ProductDesc,Quantity,Stockdate,UnitPrice,UnitPricePur,StockPrice) values('" + tbstockpc.Text + "','" + tbstockdesc.Text + "','" + tbstockqty.Text + "','" + tbstockdate.Text + "','" + tbstocksaleprice.Text + "','" + tbstockpurprice.Text + "', '" + Stprice + "' )";
SqlCommand exeSql = new SqlCommand(sql, cn);
exeSql.ExecuteNonQuery();
this.StockTableAdapter.Update(this.database1DataSet.Stock);
MessageBox.Show("Data is Updated to Database", "Stock Entered", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
cn.Close();
tbstockdesc.Text = " ";
tbstockpc.Text = " ";
tbstockpurprice.Text = " ";
tbstockqty.Text = " ";
tbstocksaleprice.Text = " ";
}
}
else
{
try
{
int Stprice = 0;
int qty = Convert.ToInt32(tbstockqty.Text);
int puprice = Convert.ToInt32(tbstockpurprice.Text);
Stprice = qty * puprice;
string sql = "insert Stock(ProductCode,ProductDesc,Quantity,Stockdate,UnitPrice,UnitPricePur,StockPrice) values('" + tbstockpc.Text + "','" + tbstockdesc.Text + "','" + tbstockqty.Text + "','" + tbstockdate.Text + "','" + tbstocksaleprice.Text + "','" + tbstockpurprice.Text + "', '" + Stprice + "' )";
SqlCommand exeSql = new SqlCommand(sql, cn);
exeSql.ExecuteNonQuery();
MessageBox.Show("Data is Inserted to Database", "Stock Entered", MessageBoxButtons.OK, MessageBoxIcon.Information);
//this.stockTableAdapter.Fill(this.database1DataSet.stock);
this.StockTableAdapter.Fill(this.database1DataSet.Stock);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
cn.Close();
tbstockdesc.Text = " ";
tbstockpc.Text = " ";
tbstockpurprice.Text = " ";
tbstockqty.Text = " ";
tbstocksaleprice.Text = " ";
}
}
}