如何在C# WinForm中按产品类型将总计值展示到另一表格？

我有两个不同的数据表，需求是将第一张表中各产品类型的总计值（例如将所有类型为“JUMBO”的产品求和），对应展示到第二张表的同类型行中。

我使用的开发环境是Visual Studio 2019下的C# Windows应用程序，数据库为SQL Server。

数据库操作类代码 #

class clsDtb
{
    const string DB_HOST = "localhost";
    const string DB_USER = "root";
    const string DB_PWD = "";
    const string DB_NAME = "rms_jl&e";
    const string CONN = @"SERVER=" + DB_HOST + ";" +
                            "UID=" + DB_USER + ";" +
                            "PWD=" + DB_PWD + ";" +
                            "DATABASE =" + DB_NAME + ";";

    //Retrieve Data
    public static DataTable QueryData(string _sql)
    {
        using (MySqlConnection _cn = new MySqlConnection(CONN))
        {
            try
            {
                _cn.Open();

                MySqlCommand _cmd = new MySqlCommand();

                _cmd.Connection = _cn;
                _cmd.CommandType = CommandType.Text;
                _cmd.CommandText = _sql;

                using (MySqlDataReader _dr = _cmd.ExecuteReader())
                {
                    DataTable dt = new DataTable();
                    dt.Load(_dr);
                    return dt;
                }
            }
            catch (Exception err)
            {
                MessageBox.Show("Error Connection " + err.Message, "Error Connection", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                return null;
            }

        }
    }

// 这是我用于从SQL获取数据表数据的类

DataGrid数据展示代码 #

string  SQL = @"SELECT  p.p_Date,prolist.prod_type ,p.p_Weight , p.p_Canister, u.FirstName
                    FROM productinventory p
                    INNER JOIN productslist prolist ON  p.prod_Code = prolist.prod_Code
                    INNER JOIN users u on p.userid = u.userid
                    ORDER BY p.p_Date DESC";
   
    private void frmProducts_Load(object sender, EventArgs e)
    {
        string userSQl = "SELECT * FROM users WHERE userid = '" + lblproid.Text.ToString() +"'";
        
        try
        {
            DataTable dtProducts = clsDtb.QueryData(SQL);
            DataTable user = clsDtb.QueryData(userSQl);
            if (dtProducts.Rows.Count > 0)
            {
                dgProducts.DataSource = dtProducts;
                
            }
            
            if (user.Rows[0]["Position"].ToString() != "Admin")
            {
                dgProducts.Columns["Delete"].Visible = false;
                dgProducts.Columns["Edit"].Visible = false;
                dgProducts.Columns["remittedby"].Visible = false;
                dgProducts.Columns["date"].Width = 200;
                dgProducts.Columns["type"].Width = 250;
                dgProducts.Columns["weight"].Width = 200;
                dgProducts.Columns["canister"].Width = 200;

            }
            else 
            {
                dgProducts.Columns["Delete"].Visible = true;
                dgProducts.Columns["Edit"].Visible = true;
                dgProducts.Columns["remittedby"].Visible = true;

            }
         }
        catch (Exception err)
        {
            MessageBox.Show("Err" + err.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
        }
        

    }

我是新手，希望大家能理解我的需求，谢谢！

内容的提问来源于stack exchange，提问作者INCOGNITO