Subject RE: [IBO] TIBOQuery param AsFloat strange behaviour
Author Jason Wharton
Post date 2018-10-26T20:31:50Z
This was due to a change I made that exposed things to a bug in one of my variant comparison routines in IB_Utils.pas.

Here is the broken code:

  function GetVarSame( const v1, v2: variant ): boolean;
  begin
    Result := VarSameValue( v1, v2 );
    if ( not Result ) and
       ( VarType( v1 ) in [ varDouble, varSingle ] ) then
      Result := FloatToStr( v1 ) = FloatToStr( v2 );
  end;

Here is the fixed code:

  function GetVarSame( const v1, v2: variant ): boolean;
  begin
    Result := VarSameValue( v1, v2 );
    if ( not Result ) then
    begin
      if ( VarType( v1 ) in [ varDouble, varSingle ] ) and
         ( not VarIsEmpty( v1 )) and
         ( not VarIsEmpty( v2 )) then
        Result := FloatToStr( v1 ) = FloatToStr( v2 );
    end;
  end;


I apologize for this and hope this helps.  For those who use my development SVN repository, this was fixed in revision 2776.
 
Kind regards,
Jason Wharton
 

From: IBObjects@yahoogroups.com [mailto:IBObjects@yahoogroups.com]
Sent: Wednesday, May 09, 2018 12:49 PM
To: IBObjects@yahoogroups.com
Subject: Re: [IBO] TIBOQuery param AsFloat strange behaviour

 

Could anyone please confirm or deny the behaviour described below? I
don't know if it's a bug in IBO 5.9.7 (I've downgraded to 5.9.3 and
everything works fine), or if I messed something up with the
configuration (although I can't imagine what possibly could cause zeros
to be replaced by nulls)?
If it's a bug, it would be worthwhile to warn the users (setting nulls
in numeric columns instead of zeros can lead to byzantine bugs on
nullable columns; imagine doing a sum(...) over such column with a
single null record within a million). But maybe I'm just overreacting.
Anyway, a three-liner is enough to reproduce this, so please try it out
and post your conclusions.

Thanks in advance and have a good one.
Tomasz

On 04.05.2018 o 13:11, Tomasz Tyrakowski t.tyrakowski@...
[IBObjects] wrote:

> Hi,
>
>
I've recently upgraded to the current (5.9.7) IBO release and was
>
surprised by a strange TIBOQuery behaviour, which forced me to downgrade
>
back to 5.9.3.
> In the latest release, when you do something
like:
>
> query.SQL.Text := 'update T set F = :val';
>
query.ParamByName('val').AsFloat := 0.0;
> query.ExecSQL;
>
>
the records get updated to NULL (!!!) instead of 0. Setting any non-zero
>
value works as expected (only 0 results in NULLs). Tested it also with a
>
freshly created table (to exclude any triggers / other dbms factors).
> In
5.9.3 the same code works well, updates F to 0.
> Delphi 10.2.3.
>
> Could anyone please confirm experiencing similar behaviour? Or is
it
> just me? Can you do a quick check with a query like above and see
what
> happens?
> I discovered it the hard way, i.e. scores of
customers started calling
> the help desk complaining about null check
errors in the app (IBO tried
> to store nulls instead of zeros in non-null
columns).
>
> regards
> Tomasz
>

--
__--==============================--__
__--== Tomasz Tyrakowski ==--__
__--== SOL-SYSTEM ==--__
__--== http://www.sol-system.pl ==--__
__--==============================--__