SqlConnection con = new SqlConnection();
con.ConnectionString = @"Data Source=.\sqlexpress;AttachDbFilename=|DataDirector y|\DbTest.mdf;Integrated Security=True;User Instance=True";
SqlCommand cmd = new SqlCommand("insert into TbInfo(id,name,family)values(@id,@name,@family)",c on);
cmd.Connection= con;
cmd.Parameters.AddWithValue("@id", textBox1.Text);
cmd.Parameters.AddWithValue("@name", textBox2.Text);
cmd.Parameters.AddWithValue("@family", textBox3.Text);
con.Open();
cmd.ExecuteNonQuery();
con.Close();