.net环境中的C#中如何连接sqlserver?求一个最短的范例程序

protected void Data()
{
String conn="Data Source=.\sqlexpress;Initial Catalog=数据库名;Integrated Security=True";
SqlConnection con = new SqlConnection(conn);
String sql = "SELECT * FROM 表名";
DataSet ds = new DataSet();
SqlDataAdapter adapter = new SqlDataAdapter(sql, con);
adapter.Fill(ds);
GridView1.DataSource =ds.Tables[0];
}

protected void GetSqlData()
{
String connStr = ConfigurationManager.ConnectionStrings["SqlConnectionString"].ConnectionString;
SqlConnection conn = new SqlConnection(connStr);
String sql = "SELECT [ProductName] FROM [Products]";
DataSet mySet = new DataSet();
SqlDataAdapter adapter = new SqlDataAdapter(sql, conn);
adapter.Fill(mySet);
GridView1.DataSource = mySet;
GridView1.DataBind();
}

string a="server=.;database=数据库名;uid=sa;pwd=密码