C#中为什么显示添加成功，数据库里面没数据呢？

string connStr = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\LYTDB.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";

            SqlConnection conn = new SqlConnection(connStr);

            conn.Open();

            string sql = "insert into tb_hy(FSheng,FShi,FXian,DSheng,DShi,DXian,HwName,HwStyle,YsStyle,Num,Weight,TiJi,Name,Yjia,Phone,Tel,SMing)values('" + cmbFSheng.Text + "','" + cmbFShi.Text + "','" + cmbFXian.Text + "','" + cmbDSheng.Text + "','" + cmbDShi.Text + "','" + cmbDXian.Text + "','" + txtHwName.Text + "','" + cmbHwStyle.Text + "','" + cmbYsStyle.Text + "','" + txtNum.Text + "','" + txtWeight.Text + "','" + txtTiJi.Text + "','" + txtName.Text + "','" + txtYjia.Text + "','" + txtPhone.Text + "','" + txtTel.Text + "','" + rtxSMing.Text + "')";

            DataSet ds = new DataSet();

            SqlCommand cmd = new SqlCommand(sql, conn);

            int i = cmd.ExecuteNonQuery();

            if (i == 1)

            {

                MessageBox.Show("恭喜，信息发布成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

            }

            else

            {

                MessageBox.Show("很抱歉，信息发布不成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);

            }

            conn.Close();