C#读取数据库的问题

Question

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection sc = new SqlConnection();
            sc.ConnectionString = @"Data Source=WWW-865F1578734;Integrated Security=True;";
                sc.Open();
            SqlCommand sg=new SqlCommand("select * from admin;",sc);
            try
            {
                sg.ExecuteNonQuery();
                MessageBox .Show ("数据库读取成功!");
            }
            catch 
            {
               MessageBox.Show("数据库读取失败!");
            }
        }
我是这样写的，可以连接上就是读数据不行，各位高手帮我看下是哪里写错了
随便告诉我如何获取读取数据库时的错误信息

Answer 1

            try 
            { 
                sg.ExecuteNonQuery(); 
                MessageBox .Show ("数据库读取成功!"); 
            } 
            catch (Exception ex)//catch到所有的异常，你可以细化
            { 
              MessageBox.Show(ex.Message); //显示错误信息
            } 

Answer 2

 SqlCommand sg=new SqlCommand("select * from admin;",sc); 
            try 
            { 
                sg.ExecuteNonQuery(); 
}
ExecuteNonQuery返回值为影响的行数.
不能读出admin的数据,用这个ExecuteReaderRetDV

Answer 3

ExecuteNonQuery 返回影响的行数
ExecuteReader 返回记录DataReader

Answer 4

 private void button1_Click(object sender, EventArgs e) 
        { 
            SqlConnection sc = new SqlConnection(); 
            sc.ConnectionString = @"Data Source=WWW-865F1578734;Integrated Security=True;"; 
                sc.Open(); 
            SqlCommand sg=new SqlCommand("select * from admin;",sc); 
            try 
            { 
                sg.ExecuteNonQuery(); 
                MessageBox .Show ("数据库读取成功!"); 
            } 
            catch 
            { 
              MessageBox.Show("数据库读取失败!"); 
            } 
        } 
似乎没有读取数据，给你个简单的例子吧，你看一下就明白了。
OracleConnection oConn;
            string strConn;
            strConn = "Data Source=***;Password=***;Persist Security Info=True;User ID=cpt;Unicode=True";
            oConn = new OracleConnection(strConn);
            try
            {
                oConn.Open();
                Frm_LogIn tempForm = new Frm_LogIn();
                String aa = publicClass1.StrUserID;
                string strOracle = "SELECT ";
                OracleCommand Cmd = new OracleCommand(strOracle, oConn);
                OracleDataReader read = Cmd.ExecuteReader();  //读取内容
                while (read.Read())
                {
                    lblUserName.Text = read[0].ToString();
                    lblUserID.Text = read[1].ToString();
                    lblUsergroup.Text = read[2].ToString();
                }
            }
            catch (Exception ex)  //抓取异常信息
            {
                MessageBox.Show(ex.Message);
            }

Answer 5

你要读取数据嘛就要用数据适配器和数据集来处理了
建议看下ADO.Net

Answer 6

private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection sc = new SqlConnection();
            sc.ConnectionString = @"Data Source=WWW-865F1578734;Integrated Security=True;";
                sc.Open();
            SqlCommand sg=new SqlCommand("select * from admin;",sc);
            try
            {
                sg.ExecuteNonQuery();  //这里是执行更新操作，你这里只是查询
                SqlDataReader sr=sg.ExecuteReader();
                MessageBox .Show ("数据库读取成功!");
            }
            catch
            {
              MessageBox.Show("数据库读取失败!");
            }
        } 

Answer 7

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection sc = new SqlConnection();
            sc.ConnectionString = @"Data Source=WWW-865F1578734;Integrated Security=True;";
            sc.Open();
            try
            {
                string sql = "select * from admin";
                DataTable dt = new DataTable("tablename");
                SqlDataAdapter da = new SqlDataAdapter(sql, sc);
                da.Fill(dt);(数据)                MessageBox.Show("数据库读取成功!");
            }
            catch (Exception ex)  //抓取异常信息 
            {
                MessageBox.Show(ex.Message);
            }
        } 

Answer 8

注意紅色部分！private void button1_Click(object sender, EventArgs e) 
        { 
            sc.ConnectionString = @"Data Source=WWW-865F1578734;Integrated Security=True;";
            SqlConnection sc = new SqlConnection(sc.ConnectionString );  
                sc.Open(); 
            SqlCommand sg=new SqlCommand("select * from admin;",sc); 
            try 
            { 
                SqlDataReader dr= sg.ExecuteReader();                if(dr.HasRows) 
                   MessageBox .Show ("数据库读取成功!"); 
                else
                   MessageBox .Show ("数据库读取失敗!或者也可能是數據庫中沒有數據！");  
            } 
            catch (Exception ex)
            { 
              MessageBox.Show(ex.Message); 
            } 
        } 

Answer 9

     顏色沒有顯出來，你自己對照一下吧。
 private void button1_Click(object sender, EventArgs e) 
        { 
            sc.ConnectionString = @"Data Source=WWW-865F1578734;Integrated Security=True;";
            SqlConnection sc = new SqlConnection(sc.ConnectionString );  [/color]
                sc.Open(); 
            SqlCommand sg=new SqlCommand("select * from admin;",sc); 
            try 
            { 
                SqlDataReader dr= sg.ExecuteReader();
                if(dr.HasRows) 
                   MessageBox .Show ("数据库读取成功!"); 
                else
                   MessageBox .Show ("数据库读取失敗!或者也可能是數據庫中沒有數據！");  
            } 
            catch (Exception ex)
            { 
              MessageBox.Show(ex.Message); 
            } 
        }