从背后的代码(C#)中读取数据库中的数据 [英] Read Data From Database In Code Behind (C#)

问题描述

他正在尝试在屏幕上显示数据库表中的数据，
我的下面的代码，但没有获取数据，请检查我的代码中的任何错误

hi am trying to display data from database table on the screen,
my code below ,but am not getting the data ,plz check any error in my code

string str = ConfigurationManager.ConnectionStrings["ConnStr"].ToString();
            SqlConnection conn = new SqlConnection(str);
            conn.Open();
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = "select error_msg from display_table where id=1001";
            cmd.CommandType = System.Data.CommandType.Text;
            SqlDataReader myDataReader;
            myDataReader = cmd.ExecuteReader();
            myDataReader.Read();
            errormsg.Text = myDataReader["error_msg"].ToString();
            myDataReader.Close();

推荐答案

您的问题已解决.试试吧


字符串str = ConfigurationManager.ConnectionStrings ["ConnStr"].ToString();
SqlConnection conn =新的SqlConnection(str);
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText =从display_table的id = 1001中选择error_msg";
cmd.CommandType = System.Data.CommandType.Text;
SqlDataReader myDataReader;
myDataReader = cmd.ExecuteReader();
myDataReader.Read();
if(myDataReader.Read())
{
errormsg.Text = myDataReader [0] .ToString();
}
myDataReader.Close();

Your Problem is solved. Try it


string str = ConfigurationManager.ConnectionStrings["ConnStr"].ToString();
SqlConnection conn = new SqlConnection(str);
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "select error_msg from display_table where id=1001";
cmd.CommandType = System.Data.CommandType.Text;
SqlDataReader myDataReader;
myDataReader = cmd.ExecuteReader();
myDataReader.Read();
if(myDataReader.Read())
{
errormsg.Text = myDataReader[0].ToString();
}
myDataReader.Close();

使用

string str = ConfigurationManager.ConnectionStrings["ConnStr"].ToString();

            SqlConnection conn = new SqlConnection(str);
            conn.Open();
             string str="select error_msg from display_table where id=1001";
            SqlCommand cmd = new SqlCommand(str,conn);
           SqlDataReader myDataReader=cmd.ExecuteReader();
           
          if(myDataReader.Read())
{
errormsg.Text = myDataReader["error_msg"].ToString();
}
else
{
errormsg.Text="data not found";
}
          
cmd.Connection.Close();

DataReader在连接模式下工作.

请查看下面的链接，以获取有关DataReader的更多信息.

http://msdn.microsoft.com/en-us/library/haa3afyz (v = VS.100).aspx

DataReader works in a Connected mode.

Have a look at below link for more information on DataReader.

http://msdn.microsoft.com/en-us/library/haa3afyz(v=VS.100).aspx

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