Question

我有一个表单，如果用户在文本框中键入隐藏问题的正确答案，它将转到数据库中下一个随机选择的记录，并在数据库的player表中的playerscore列添加+1。但是，分数不会在数据库或标签中更新。

我已经删除了这篇文章中的所有其他代码，例如连接字符串，但它就在那里并且正在建立连接。

    private void SubmitAnswer_Click(object sender, EventArgs e)
    {
        int score = 0;

        if (WordBox.Text == WordLbl.Text)
        {
            TopLbl.Text = "Well done! :)";
            synthesizer.SpeakAsync("Well done. Now try answering this...");
            this.BackColor = System.Drawing.Color.OliveDrab;

            String command = "SELECT TOP 1 * FROM Questions ORDER BY Rnd(-(100000*ID)*Time())";

            try
            {
                FillDataTable(command);
                ShowRow(currentRow);

                score++; // Adding one each time the player spells the word correctly.
                ScoreLabel.Text = "Score: " + score.ToString(); // Update the label to display new score.
                myAdapter.SelectCommand.CommandText = "UPDATE Questions SET players = playerscore + 1 WHERE ID =" + currentRow;
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

            synthesizer.SpeakAsync("Answer the question" + WordLbl.Text); 
        }

        else
        {
            TopLbl.Text = "Try answering this question again";
            synthesizer.SpeakAsync("Try answering this question again");
            this.BackColor = System.Drawing.Color.Red; color on the form.
        }
    }

我怀疑这可能低至currentRow。在该计划的顶部：

// Index of the current record private int currentRow = 0;

ShowRow类

    private void DisplayRow(int rowIndex)
    {
        if (myDataTable.Rows.Count == 0)
        return; 

        if (rowIndex >= myDataTable.Rows.Count)
        return; 

        try
        {
            DataRow row = myDataTable.Rows[rowIndex];
            KS1WordLbl.Text = row["Word"].ToString();
            synthesizer.SpeakAsync("Answer the question" + WordLbl.Text);
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error in DisplayRow : \r\n" + ex.Message);
        }

    }

Answer 1

假设FillDataTable填充myDataTable及其范围，您应该能够将where子句更新为

where id = " + myDataTable.Rows[0].[id].ToString()

您当前正在尝试做的更像是就地更新，您需要做的是提取记录ID并使用它来告诉db要更新哪条记录

请注意，虽然您不必担心SQL注入攻击，因为ID不受用户控制，您应该查看参数化查询。

在C＃和Access中更新当前记录不起作用

1 个答案: