c＃mysql - 在描述相同时添加stock和new条目的值

Question

对不起我的英语..

当我在datagridview中插入记录与现有记录相同的描述但数量不同时...它为我插入的最后一条记录创建了一个新行......

我想要的是添加我插入到具有相同描述的旧记录的数量..

1. HERE'S THE IMAGE FOR YOU TO UNDERSTAND THE PROBLEM

2. THIS IS WHAT HAPPEN

结果应该是QUANTITY = 25 ..还有totalcbm .. totalcbm = quantity * cbm

    private void btnSave_Click(object sender, EventArgs e)
    {
        MySqlConnection connection = new MySqlConnection(MyConnectionString);
        MySqlCommand cmd;
        connection.Open();

        try
        {
            cmd = connection.CreateCommand();
            cmd.CommandText = "INSERT INTO Inventory(Quantity,Unit,ItemCode,ItemName,Cbm,TotalCbm)VALUES(@Quantity,@Unit,@ItemCode,@ItemName,@Cbm,@TotalCbm)";
            cmd.Parameters.AddWithValue("@Quantity", tbQuantity.Text.ToString());
            cmd.Parameters.AddWithValue("@Unit", tbUnit.Text.ToString());
            cmd.Parameters.AddWithValue("@ItemCode", tbItemCode.Text.ToString());
            cmd.Parameters.AddWithValue("@ItemName", tbItemName.Text.ToString());
            cmd.Parameters.AddWithValue("@Cbm", tbCbm.Text.ToString());
            cmd.Parameters.AddWithValue("@TotalCbm", tbTotalCbm.Text.ToString());
            cmd.ExecuteNonQuery();
        }

        catch (Exception)
        {
            throw;
        }

        finally
        {
            if (connection.State == ConnectionState.Open)
            {
                connection.Close();
                frmUserAE form1 = new frmUserAE();
                AccountForm.LoadGrid();
                this.Hide();
            }
        }


    }

Answer 1

您正在执行INSERT语句，该语句将创建一个新行。

您应该执行UPDATE语句，具体取决于您认为的主键（描述？）。