Ok use this code
using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;
onn.Open();
// The command settings
SqlCommand oCommand = new SqlCommand("Select * From Employee",oConn);
SqlDataAdapter oAdapter = new SqlDataAdapter(oCommand);
/* we use here data table rather than a data source because
we want just to bind a field to our textbox*/
DataTable oTable = new DataTable();
//Fill data into the data table
oAdapter.Fill(oTable);
/*We don't need the connection new as we consume data from the on memory
* cached data table so we close the connection*/
oConn.Close();
/* Assuming that we need to bind textBox1 to the FirstName Field of
* the employee table*/
textBox1.DataBindings.Add("Text", oTable, "FirstName");
Unsolved 
