Converting Object to Short

[sweatha]

Hi

I have to select count(Date) from Appointment table having count<5. If count(Date)<5 then I should insert the data from my page. For that I have given the coding as

protected void Button3_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection("user id=sa;password=cast;database=Hello_Dr;server=AURORA-SERVER;");
        con.Open();
        SqlDataReader rd;
        SqlCommand cmd = new SqlCommand();
        cmd.Connection = con;
        cmd.CommandText = "select count(Date) from Appointment where Date='" + DateTextBox.Text + "'"; 
        //and count(Date)>=5";
 
        Int16 cnt;
        cnt = cmd.ExecuteScalar();
        if (cnt >= 5)
        {
            Response.Write("Plz select another appointment date");
        }
        else
        {
 
            String sql = "insert into Appointment values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + TextBox3.Text + "','" + DateTextBox.Text + "','" + TextBox5.Text + "','" + TextBox6.Text + "','" + TextBox7.Text + "','" + TextBox8.Text + "')";
            SqlCommand cmd1 = new SqlCommand(sql, con);
            cmd1.ExecuteNonQuery();
        }
      }
 

But when I run, I am getting the following error.


Error 1 Cannot implicitly convert type 'object' to 'short'. An explicit conversion exists (are you missing a cast?) E:\suganya\Suganya_Hello_Dr\Appointment.aspx.cs 93 15 E:\suganya\Suganya_Hello_Dr\

[Plater]

If an explicit conversion exists (as it says), you can type-cast it with (short)

[mbewers1]

I tried type-casting the return value for ExecuteScalar() to int in the following code:

using (SqlConnection sqlCon = new SqlConnection(ConnectionString))
            {
                sqlCon.Open();
                SqlCommand command = sqlCon.CreateCommand();
                command.CommandType = CommandType.Text;
                command.CommandText = @"SELECT COUNT(*) 
                    FROM Staff WHERE Phone = @phone AND Email = @email";
 
                command.Parameters.Add("@phone", SqlDbType.Char, 9).Value =
                    prop.Phone;
                command.Parameters.Add("@email", SqlDbType.VarChar, 50).Value =
                    prop.Email;
                return command.ExecuteScalar();
            }
 

but when I try to access the return value, using an int variable in my code-behind page for a Windows Form, I get a result of 0 every time. I've tried applying the query in SQL Query Analyser and I've got > 0 back, so I know it works.

I've also tried using Convert.ToInt32 and that didn't work either:

int off = Convert.ToInt32(
                FormStaffManager.Instance.CheckExistingStaff(prop));
            return off;
 

Anyone knows how I can convert object to int successfully?

[vekipeki]

This should work:

int cnt = (int)cmd.ExecuteScalar();

If you are getting 0, then your SqlCommand actually returns 0. Try to add this and set a breakpoint to check the actual object value:

// set a breakpoint after this line
object result = cmd.ExecuteScalar();

[mbewers1]

thanks, that worked a treat.

So did this:

int result = command.ExecuteNonQuery();
return result;

.. as I needed to return a value in the method.

thanks

[Frinavale]

Um, I think the most obvious thing here is the ExecuteScalar() method is returning a Short, and therefor your "cnt" variable should be of type Short.....

Short cnt;
cnt = cmd.ExecuteScalar();

There's really no reason why casting should be used here since you know the type is a Short.


The other thing is that you shouldn't be using the Response.Write() method like you are. See this post for more details on why.

[Curtis Rutland]

ExecuteScalar returns an object, and C# requires explicit casting, so you would have to cast your return value to the proper type.