How to use SQL Data Reader to check quantity in database? - sqldatareader

Question

I want to check quantity in the tblProducts with the quantity selected by the user. If the user selects more than in tblProducts, there will be a pop up message and the quantity will not added. If there is available quantity in tblProducts, the user can add the quantity. Do I need to put SP_UpdateCart in both if statement?
if (e.CommandName == "DoPlus")//Check quantity here
{
string PID = (e.CommandArgument.ToString());
using (SqlConnection con = new SqlConnection(CS))
{
SqlCommand cmd = new SqlCommand("SP_getUserCartItem", con)
{
CommandType = CommandType.StoredProcedure
};
cmd.Parameters.AddWithValue("#PID", PID);
cmd.Parameters.AddWithValue("#UserID", UserID);
using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
sda.Fill(dt);
con.Open();
using (SqlDataReader dr = cmd.ExecuteReader())
{
while (dr.Read())
{
int myQty = Convert.ToInt32(dr["Qty"].ToString());
int PQuantity = Convert.ToInt32(dr["PQuantity"].ToString());
if (dt.Rows.Count > 0)
{
if (myQty < PQuantity)
{
Int32 updateQty = Convert.ToInt32(dt.Rows[0]["Qty"].ToString());
SqlCommand myCmd = new SqlCommand("SP_UpdateCart", con)
{
CommandType = CommandType.StoredProcedure
};
myCmd.Parameters.AddWithValue("#Quantity", updateQty + 1);
myCmd.Parameters.AddWithValue("#CartPID", PID);
myCmd.Parameters.AddWithValue("#UserID", UserID);
con.Open();
Int64 CartID = Convert.ToInt64(myCmd.ExecuteScalar());
con.Close();
BindProductCart();
BindCartNumber();
}
else if (myQty > PQuantity)//check quantity between tblCart and
tblProducts
{
Response.Write("<script>alert('Please choose quantity less than
stated!');</script>");
Int32 updateQty = Convert.ToInt32(dt.Rows[0]["Qty"].ToString());
SqlCommand myCmd = new SqlCommand("SP_UpdateCart", con)
{
CommandType = CommandType.StoredProcedure
};
myCmd.Parameters.AddWithValue("#Quantity", updateQty);
myCmd.Parameters.AddWithValue("#CartPID", PID);
myCmd.Parameters.AddWithValue("#UserID", UserID);
con.Open();
Int64 CartID = Convert.ToInt64(myCmd.ExecuteScalar());
con.Close();
BindProductCart();
BindCartNumber();
}
}
}
dr.Close();
}con.Close();
}
}
}