如何在将 dataTable 中的数据显示到 dataGridView 之前对其进行编辑？

Question

我正在做一个 C# Windows 窗体应用程序。我想让你先了解一些事情。我正在使用本地访问数据库。我一直在尝试将月份从 AccessDB 转换为 MonthName。好吧，我尝试过使用 DATENAME 函数，但它无法正常工作。所以我想我是否可以在将数据表放入 datGridView 进行显示之前对其进行编辑。请帮帮我。请看代码。

private void button3_Click(object sender, EventArgs e) // display amount havent cleared the month yet
    {
        sum.Visible = true;
        // 1
        // Open connection\
        string companyName = comboBox1.Text;
        string connectionString = null;
        OleDbConnection conn = null;
        connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=DPE2.mdb;";
        conn = new OleDbConnection(connectionString);
        {
            conn.Open();
            // 
            // Create new DataAdapter
            using (OleDbDataAdapter a = new OleDbDataAdapter(
                "SELECT MONTH(Date) AS [Month], SUM(Amount) AS [Amount] FROM Statements Where Customer_name ='" + companyName + "' group By MONTH(Date)", conn))
            {
                // 3
                // Use DataAdapter to fill DataTable
                DataTable t = new DataTable();
                a.Fill(t);
                // 4
                // Render data onto the screen
                dataGridView3.DataSource = t; 
            }

            int z = 0;
            while (z < dataGridView3.Rows.Count)
            {
                string data = dataGridView3.Rows[z].Cells[0].ToString();

                switch (data)
                {
                    case "1":
                        dataGridView3.Rows[z].Cells[0].Equals("Jan");
                        break;
                    case "2":
                        dataGridView3.Rows[z].Cells[0].Value = "Feb";
                        break;
                    case "3":
                        dataGridView3.Rows[z].Cells[0].Value = "Mar";
                        break;
                    case "4":
                        dataGridView3.Rows[z].Cells[0].Value = "April";
                        break;
                    case "5":
                        dataGridView3.Rows[z].Cells[0].Value = "May";
                        break;
                    case "6":
                        dataGridView3.Rows[z].Cells[0].Value = "June";
                        break;
                    case "7":
                        dataGridView3.Rows[z].Cells[0].Value = "July";
                        break;
                    case "8":
                        dataGridView3.Rows[z].Cells[0].Value = "August";
                        break;
                    case "9":
                        dataGridView3.Rows[z].Cells[0].Value = "September";
                        break;
                    case "10":
                        dataGridView3.Rows[z].Cells[0].Value = "October";
                        break;
                    case "11":
                        dataGridView3.Rows[z].Cells[0].Value = "Novemeber";
                        break;
                    case "12":
                        dataGridView3.Rows[z].Cells[0].Value = "December";
                        break;
                }
                z++;
            }

        }
    }

Answer 1

您可以尝试像这样更改您的选择查询。

SELECT convert(char(3), Date, 0) AS [Month], SUM(Amount) AS [Amount] FROM Statements Where Customer_name ='" + companyName + "' group By MONTH(Date)"

这将直接以 3 个字母为您提供月份，因此需要实现额外的逻辑来处理 datagridView 单元格文本以将月份设置为 3 个字母。

或者，如果您不想更改您的查询，那么实现将在 dataTable 中为 3 个字母月份添加一个额外列（如 MonthText）的逻辑。然后将这个新表与您的 DataGridView 绑定。