不能更新...

SqlCommand update = new SqlCommand("update news set senddate='" + riqi.Text.ToString() + "',contents='" + neirong.Text.ToString() + "',diqu='" + fenzhan.Text.ToString() + "',fenlei='" + fenlei.Text.ToString() + "' where id='" + HiddenField1.Value + "'", conn);
conn.Open();
update.ExecuteReader();
conn.Close();


这段代码当中
diqu='" + fenzhan.Text.ToString() + "',fenlei='" + fenlei.Text.ToString() + "'
正常更新

senddate='" + riqi.Text.ToString() + "',contents='" + neirong.Text.ToString() + "'
却更新不了

没有任何错误提示，不知道错在哪里了