从数据库加载一些值（C＃） [英] Load some values from database (C#)

问题描述

我尝试在测试系统的面板中从数据库加载一些值。

我想在面板上加载随机的20个值：

I try to load some values from database in a panel for a test system.
I want to load random 20 values on a panel:

private void panel1_Paint(object sender, PaintEventArgs e)
{
    string connection = "Data Source=H-AHMADRAZA;Initial Catalog=TestSys;Integrated Security=True";
    SqlConnection conn = new SqlConnection(connection);
    string query = "select q.Question,q.Option1,q.Option2,q.Option3,q.Option4,a.Answer from Questions q,Answers a where q.Q_ID= 'MATH' and q.ID=a.ID;";
    SqlCommand cmd = new SqlCommand(query, conn);
    //reader = cmd.ExecuteReader();
    SqlDataReader reader;
    conn.Open();
    try
    {
        reader = cmd.ExecuteReader();
        while (reader.Read())
        {
            for (int i = 0; i < 20; i++)
            {
                lblQuestion.Text = Random.Next();
                rdiobtna.Text = Random
                    rdiobtnb.Text=Random
                        rdiobtnc.Text=Random
                        rdiobtnd.Text=Random
                            lblAnswer.Text=Random
            }
        }
    }
    catch (Exception)
    {

        throw;
    }
    finally {
    conn.Close();
    }
}

推荐答案

你可以直接从sql server中随机选择n行。那么你不必担心如何在后面的代码中随机选择行。

查看下面你可以使用的sql语法的问题和答案。

[ ^ ]

you can randomly select n number of rows directly from sql server. then you don't need to worry about how to randomly select rows in the code behind.
check below question and answers for the sql syntax you can use.
Select n random rows from SQL Server table[^]

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