You can use single or double quotes to fix this problem. My guess would be that SQL Select parser doesn't process string encloused in [] delimiters properly

Select ;
     "a?b" as Url ;
   From < table >
* or
Select ;
     'a?b' as Url ;
   From < table >

>On of our SQL statements has a field which contains a "?".
>
>I ran a simple test.
>
>

>Select ;
>     [a?b] as Url ;
>   From < table >
>

>
>The question mark disappears. Below fixes the problem.
>
>

>Select ;
>     [a] + Chr(63) + [b] as Url ;
>   From < table >
>

>
>I'm betting this has been documented already. What is the reason for this behavior?
>
>TIA