baglanti.Open();
            sql_da = new SqlDataAdapter("SQL KODUNUZ", baglanti);
            DataTable tablo = new DataTable();
            sql_da.Fill(tablo);
            gridControl57.DataSource = tablo; //devexpress grid kullanıldı
            baglanti.Close();

sql_cmd = new SqlCommand();
                baglanti.Open();
                sql_cmd.Connection = baglanti;
                sql_cmd.CommandText = "SQL KODUNUZ";
                object varmi = sql_cmd.ExecuteScalar();
                string Saat = (Convert.ToString(varmi).Substring(0, 5));
                baglanti.Close();

public partial class Form1 : Form
    {

SqlConnection baglanti = new SqlConnection(@"Data Source=192.168.1.10\SQLEXPRESS; Initial Catalog=databaseadi; User ID=username; Password=sifre");
        
        SqlCommand sql_cmd;
        SqlDataAdapter sql_da;
        SqlDataReader sql_dr;

class Kişi{
			public string Ad {get; set;}
			public string Soyad {get; set;}
		}
		void Button1Click(object sender, EventArgs e)
		{

			var con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\goksen\Documents\liste.xlsx;Extended Properties='Excel 12.0;HDR=No;'");

			con.Open();
			var cmd = new OleDbCommand("Select * From [Sheet 1$]", con);
			var dr = cmd.ExecuteReader();
			var list = new List<Kişi>();
			while (dr.Read())
			{
				list.Add(new Kişi { Ad = dr[0].ToString(), Soyad = dr[1].ToString() });
			}
			con.Close();
			dataGridView1.DataSource=list;
		}