Dynamically setting LINQ datasource results in Operator '==' incompatible with operand types 'String' and 'Int32'

Question

I'm trying to dynamically set my where statements for a linq datasource, and it was working fine until I try to add another constraint.

This code works here:

private void SetDataSourceWhereStatement()
    {
        HttpCookie cookie = Request.Cookies[ "CustomerID" ];

        if ( cookie == null )                                           //set data source where statement to default
            ldsCustomerLinks.Where = "CustomerID == -1";
        else ldsCustomerLinks.Where = "CustomerID == " + cookie.Value;  //set data source where statement

        ldsCustomerLinks.Where = ldsCustomerLinks.Where + " && CategoryID == " + m_CategoryID;
        ldsCustomerLinks.DataBind();
    }

However, when I also try and add a customer number, I get the error. This is the code I'm attempting to use:

private void SetDataSourceWhereStatement()
    {
        HttpCookie cookie = Request.Cookies[ "CustomerID" ];
        HttpCookie cookie2 = Request.Cookies[ "CustomerNumber" ];

        if ( cookie == null )                                           //set data source where statement to default
            ldsCustomerLinks.Where = "CustomerID == -1";
        else ldsCustomerLinks.Where = "CustomerID == " + cookie.Value;  //set data source where statement

        if ( cookie2 != null )
            ldsCustomerLinks.Where += " && CustomerNumber == " + cookie2.Value;
      //  else ldsCustomerLinks.Where += " && CustomerNumber >= 0";

        ldsCustomerLinks.Where = ldsCustomerLinks.Where + " && CategoryID == " + m_CategoryID;
        ldsCustomerLinks.DataBind();
    }

Both cookie and cookie2 values are strings. I've tried converting it using int.parse, int32.parse, using the value's .toString() methods and trying everything all over. I don't understand what's wrong.

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EDIT::

So I got my answer, from one of the below posts, but I do not understand, could someone please explain why my original code did not work but the revised does?

Old code:

if ( cookie2 != null )
            ldsCustomerLinks.Where += " && CustomerNumber == " + cookie2.Value;

New code:

if ( cookie2 != null )
            ldsCustomerLinks.Where += @" && CustomerNumber == (""" + cookie2.Value + @""") ";

Answer 1

You say cookie and cookie2 are strings... what about m_CategoryID?

have you tried

ldsCustomerLinks.Where = ldsCustomerLinks.Where + " && CategoryID == " + m_CategoryID.ToString();

---

OK - I was suspicious of the lack of quotes for CustomerNumber in the 'Where' string, but not confident enough to post it as a suggestion (having a bad SO day!)

So to answer the second question:

the type mismatch comes within the database, where CustomerNumber (I am inferring) is a string, but you are building a query with a number, like

CustomerID == 312 && CustomerNumber == 45654789 && CategoryID == 3

where you should be saying

CustomerID == 312 && CustomerNumber == "45654789" && CategoryID == 3

and to get the quotes within a string (which is enclosed by quotes) you need to use the """ syntax.

Answer 2

Forgive me, without much knowledge about this LINQ usage my answer might be totally off.

This question seems to be related though and suggests that you parse/convert the (quoted in that case!) value.