在c＃ASP.Net中查找当天的当前日期

Question

I want to find current day of week in c# ASP.Net like:

System.DateTime.Now.DayOfWeek.ToString(); 

This code works well in a console application, but when I try to store the value of this line in a string in ASP.Net website it returns nothing.

Can anyone help?

StringBuilder message = null;

protected void Page_Load(object sender, EventArgs e)
{
    var dayofweek = System.DateTime.Now.DayOfWeek.ToString();
    String conn = "Data Source=.;Initial Catalog=OCSI;Integrated Security=True";//conne
    SqlConnection sqlconne = new SqlConnection(conn);

    string selectSQL = "SELECT lec FROM schedule WHERE [day]='" + dayofweek +"'";
    SqlCommand cmd = new SqlCommand(selectSQL, sqlconne);
    SqlDataReader reader = null;
    try
    {
        sqlconne.Open();
        reader = cmd.ExecuteReader();
        message = new StringBuider(); 
        while (reader.Read())
        {
            message.Append(reader["lec"].ToString());
           //question what are you using message for ...?
            Label3.Text = dayofweek;
        }
        reader.Close();
    }
    catch (Exception ex)
    {
        Response.Write(ex.Mesage);
    }
    finally
    {
        sqlconne.Close();
        // you neeed to Dispose of all other objects here too
        // StringBuilder Object
        // SqlDataReader Object
        //SqlCommand  Object.. 
        //Look into wrapping your Connection / Command Sql Dataobject around a using() {}
    }

I want to use current day in where clause SQL Query to get data relevant to current day from database table.

I used var as

 protected void Page_Load(object sender, EventArgs e)
 {
    String conn = "Data Source=.;Initial Catalog=OCSI;Integrated Security=True";//conne
    SqlConnection sqlconne = new SqlConnection(conn);

    var testDay = DateTime.Now.DayOfWeek.ToString();

    // string selectSQL = "SELECT lec FROM schedule WHERE [day]='" + dayofweek +"'";
    string selectSQL = string.Format("SELECT lec FROM schedule WHERE [day]= {0}", testDay);
    SqlCommand cmd = new SqlCommand(selectSQL, sqlconne);
    SqlDataReader reader;
    try
    {
        sqlconne.Open();
        reader = cmd.ExecuteReader();

        while (reader.Read())
        {
            message += reader["lec"].ToString();

            Label3.Text = testDay;
        }
        reader.Close();
    }
    catch
    { 
    }
    finally
    {
        sqlconne.Close();
    }

Answer 1

It works fine for me.

Answer 2

Wep page is the value defined as a public , static, or property..

if you write

var testDay = DateTime.Now.DayOfWeek.ToString();

the results will = "Friday";

Answer 3

作为整数值（系统将星期日设为0）=

int day = (int)DateTime.Now.DayOfWeek;

Answer 4

Also try changing your sql string to this

string selectSQL = 
   string.Format("SELECT lec FROM schedule WHERE [day]= {0}", dayofweek);

Answer 5

if everything is working fine when you remove the where clause then change the Where clause to be something like this

   string selectSQL = string.Format("SELECT lec FROM schedule WHERE dbo.schedule.day = {0} ", testDay);

I would also change the name of the field day to something like DayName or something if day is a Reserved word don't use it.. look at this link for Reserved Words in SQL Reserved SQL Words