Question

我需要从数据库中随机选择昵称，并将这些昵称显示给多个标签。

我的代码在所有这些标签中只显示一个昵称，但我需要在按钮后点击随机昵称，数据库中的内容，在标签中显示。

void Button1Click(object sender, EventArgs e)
        {
            OleDbConnection connection = new OleDbConnection();
            connection.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=names.mdb";
            connection.Open();
            OleDbCommand command = new OleDbCommand();
            command.Connection = connection;
            command.CommandText = "SELECT ID,nickname FROM names where ID=3 ";
            OleDbDataReader reader = command.ExecuteReader();
            while (reader.Read()){
                label1.Text=reader["nickname"].ToString();
                label2.Text=reader["nickname"].ToString();
                label3.Text=reader["nickname"].ToString();
                label4.Text=reader["nickname"].ToString();
                label5.Text=reader["nickname"].ToString();
                label6.Text=reader["nickname"].ToString();
                label7.Text=reader["nickname"].ToString();
                label8.Text=reader["nickname"].ToString();
            }
            connection.Close(); 
        }

表格的例子 http://greenlight.ucoz.lv/11cqsvX/ac_lb.png

到label1 nickname1，标签2昵称26，标签3昵称78， ...

请帮助我，抱歉我的英语不好：）

Answer 1

我的想法是将SQL修改为select a random row，因为您当前的SQL将始终选择相同的行。通过迭代每个标签为每个标签执行此操作。

private void button1_Click(object sender, EventArgs e)
{
  OleDbConnection connection = new OleDbConnection();
  connection.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=names.mdb";
  connection.Open();

  foreach (Control control in Controls)
  {
    if (control is Label)
    {
      OleDbCommand command = new OleDbCommand();
      command.Connection = connection;
      command.CommandText = "SELECT nickname FROM names ORDER BY rnd(ID)";
      OleDbDataReader reader = command.ExecuteReader();
      reader.Read();
      control.Text = reader["nickname"].ToString();
    }
  }
  connection.Close();
}

Answer 2

得到答案，现在我的代码看起来

OleDbConnection connection = new OleDbConnection();
            connection.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=names.mdb";
            connection.Open();
            OleDbCommand command = new OleDbCommand();
            command.Connection = connection;
            command.CommandText = "SELECT ID,nickname FROM names ORDER BY rnd(ID)";
            foreach (Control control in Controls)
  {
    if (control is Label)
    {
      OleDbDataReader reader = command.ExecuteReader();
      reader.Read();
      control.Text = reader["nickname"].ToString();
      reader.Close();
    }
  }
            connection.Close();

谢谢@MikeB

标签从数据库c＃中放入随机值

2 个答案: