Re: [Cppcms-users] Bizarre prepared statement problem

[Artyom B. <art...@ya...>]

 


----- Original Message -----
> From: Artyom Beilis <art...@ya...>
> To: "cpp...@li..." <cpp...@li...>
> Cc: 
> Sent: Tuesday, May 22, 2012 7:58 PM
> Subject: Re: [Cppcms-users] Bizarre prepared statement problem
> 
> 
> 
>>  cppdb::result Base::get_all_items(...)
> 
>>  {
>> 
>>      cppdb::result r;
>>      string ts = "2012-05-17 23:59:59";
>>      ...
>>      r=sql ....
>>      << date_limited_only
>>      << ts
>>      << ts
>>      << ts
>>          << aircraft_id;
>> 
>>      return r;   // <----
>>  }
>> 
> 
> And than in some other place
> 
> r = get_all_times(...)
> while(r.next()) 
>   ...
> 
> In the first request of r.next() the query is actually
> executed, when **ts** goes out of the scope and becomes invalid.
> and during query the ts is not valid.
> 
> That is why it does not work.
> 
> I can suggest switch to:
> 
> get_all_times
> {
>   r = sql ....
>   r.next();
>   return r;
>    
> }
> 
> r=get_all_times();
> 
> while(!r.empty())  {
>   r >> ...
>   r.next()
> }
> 
> Artyom Beilis
>



On the second thought...


It is bug because it is really unexpected behavior..

And stuff like this


  r = sql << "SELECT ... ? .. "  << (a+b);

  while(r.next()) {
    
  }

Would not work properly

Please open a bug report with HIGH priority

Thanks for the enlightenment! 

Artyom