从csv文件替换数据库中的数据

我正在创建一个基于Windows的应用程序来读取csv文件并在datagridview中显示。csv文件由item_no和stock组成。

我有两个按钮，添加数据和替换数据。

使用add data，添加相同的item_no stock，然后将其插入数据库。在数据库中，库存被添加到特定item_no的现有库存中。

使用替换数据，添加相同的item_no股票，然后将其替换为数据库中item_no的股票。

我可以在数据库中添加股票，但我不能在数据库中替换股票。

这是我的代码来替换数据，这更像是添加股票，

try
   {
     //we need to copy the data from datagridview into data table
     DataTable dtable = new DataTable();
     dtable.TableName = "Product";
     foreach (DataGridViewColumn col in dataGridView1.Columns)
     {
        dtable.Columns.Add(col.DataPropertyName, col.ValueType);
     }
            foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                if (row.IsNewRow)
                    continue;

                DataRow dtRow = dtable.NewRow();

                for (int i = 0; i < dataGridView1.Columns.Count; i++)
                    dtRow[i] = (row.Cells[i].Value == null ? DBNull.Value : row.Cells[i].Value);

                dtable.Rows.Add(dtRow);
            }

            foreach (DataRow dr in dtable.Rows)
            {
                string itemNo = null;
                string itemName = null;
                double cost = 0.00;
                double price = 0.00;
                double Stock = 0.00;
                int dept = 1;
                double tax1 = 0;
                double tax2 = 0;
                double BulkPrize = 0.00;
                double BulkQty = 0.00;
             //   double finalStock = 0.00;
                itemNo = Convert.ToString(dr[0]);

                if (dr[1] != DBNull.Value)
                    itemName = Convert.ToString(dr[1]);


                if (dr[2] != DBNull.Value)
                    price = Convert.ToDouble(dr[2]);


                if (dr[3] != DBNull.Value)
                    cost = Convert.ToDouble(dr[3]);

                Stock = Convert.ToDouble(dr[4]);
               // finalStock = finalStock + Stock;

                if (dr[5] != DBNull.Value)
                    dept = Convert.ToInt32(dr[5]);

                if (dr[6] != DBNull.Value)
                    tax1 = Convert.ToDouble(dr[6]);

                if (dr[7] != DBNull.Value)
                    tax2 = Convert.ToDouble(dr[7]);

                string sql_select = "select count(*) from PRODUCTS where item_no= '" + itemNo + "'";
                SqlCommand cmdCheckPmk = new SqlCommand(sql_select, Class1.conn);

                int selectItemNo = Convert.ToInt32(cmdCheckPmk.ExecuteScalar());

                if (selectItemNo != 0)
                {
                    string sql_update = "update PRODUCTS set item_stock=+'" + Stock + "' where item_no= '" + itemNo + "'";
                    SqlCommand cmd1 = new SqlCommand(sql_update, Class1.conn);
                    cmd1.ExecuteNonQuery();

                }
                else
                {
                    SqlCommand cmd11 = new SqlCommand("insert into PRODUCTS(item_no,item_name,price,cost,item_stock,dept_id,tax_rate1,tax_rate2,bulk_price,bulk_qty) values ('" + itemNo + "','" + itemName + "'," + price + "," + cost + "," + Stock + ",'" + dept + "','" + tax1 + "','" + tax2 + "'," + BulkPrize +"," + BulkQty +") ", Class1.conn);
                    cmd11.ExecuteNonQuery();
                }
            }

            MessageBox.Show("Data Replace Successfully ..!!", "Congrats", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
        catch (System.Data.SqlClient.SqlException exe)
        {
            if (exe.Number == 547)
            {
                MessageBox.Show("Add Department in Corner Store First..!!", "Add Department in Corner Store", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            else
            {
                MessageBox.Show(exe.Message, "Error in replace - Option 3 Insert/Update", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }

有人能帮我吗?

谢谢。

Rushabh

string sql_update = "update PRODUCTS set item_stock=+'" + Stock + "' where item_no= '" + itemNo + "'";

string sql_update = "update PRODUCTS set item_stock='" + Stock + "' where item_no= '" + itemNo + "'";

string sql_update = "update PRODUCTS set item_stock='" + Stock + "' where item_no = " + itemNo ;