🚀 go-pugleaf

Gabriele Cardinali (febeaweb@febea.it) wrote:
: Partial search doesn't work with expression indexes???
: Please, tell me not!!!!!!!!!!

Sorry, but it doesn't.  I recall reading a work-around in the
Lloyd's Delphi help file, a Windows help file full of useful
information, which is available from http://www.inprise.com/
and a number of other websites.
--
============================================================
Rick Carter   carterrk@email.uc.edu   rcarter@tso.cin.ix.net
============================================================

Your example shows keyfield count as ONE. Could that be your problem?
You are searching on 2 fields, no? I suspect keyfieldcount will not work
anyway, because Delphi is stupid when it comes to expression indexes. 
It doesn't know which fields are in the expression, or probably how many
fields are in it.

Furthermore, I don't know what "TTable.IndexKey" is. I use dBASE
expression indexes all the time, and have never encountered that. 
IndexName, yes.

Try this, instead:

with mytable do
begin
  Setkey;
  Fieldbyname('FIELD1').asstring:=key1;
  Fieldbyname('FIELD2').asstring:=key2;
  Fieldbyname('FIELD3').asstring:='';
  Gotonearest;
  if (Fieldbyname('FIELD1').asstring<>key1)
  and (Fieldbyname('FIELD2').asstring<>key2)
  then showmessage ('BARF!');
end;

PLUS, remember that your keys will be case-sensitive, unless your
expression specifies otherwise, with the UPPER function! This could be
your problem, too...

Let me know how it goes...

DMGoncalves


Gabriele Cardinali wrote:
> 
> Please, help me!!!!
> I have a DBF table with some fields. I have created an expression index
> in this way:
>   myTable.AddIndex('myIndex','Field1+Field2+dtos(Field3)',[ixExpression,
> ixDescending])
> 
> I have to do a partial search on Field1 and Field2.
> So I do the following:
> 
>   myTable.IndexKey:='myIndex';
>   myTable.SetKey;
>   myTable.KeyfieldCount:=1; { to use Field1 and Field2 }
>   myTable.FieldByName('Field1').AsString:='aaaaaa';
>   myTable.FieldByName('Field2').AsString:='bbbbb';
>   myTable.GotoKey;
> 
> but this source doesn't work. I have tried also with GotoNearest.
> Partial search doesn't work with expression indexes???
> Please, tell me not!!!!!!!!!!
> Please help me and, however, thanks for your interesting.
> Thanks once again.

I've done partial searches a lot using DBF files with no trouble.
See notes below.

bill wester



On Tue, 21 Jul 1998 17:24:46 +0200, Gabriele Cardinali
<febeaweb@febea.it> wrote:

>Please, help me!!!!
>I have a DBF table with some fields. I have created an expression index
>in this way:
>  myTable.AddIndex('myIndex','Field1+Field2+dtos(Field3)',[ixExpression,
>ixDescending])
>
>I have to do a partial search on Field1 and Field2.
>So I do the following:
>
>  myTable.IndexKey:='myIndex';
>  myTable.SetKey;
cut{>  myTable.KeyfieldCount:=1; { to use Field1 and Field2 }}
>  myTable.FieldByName('Field1').AsString:='aaaaaa';
>  myTable.FieldByName('Field2').AsString:='bbbbb';
cut{>  myTable.GotoKey;}
    myTable.GoToNearest;        --> always works for me.
				I have never used KeyfieldCount

>
>but this source doesn't work. I have tried also with GotoNearest.
>Partial search doesn't work with expression indexes???
>Please, tell me not!!!!!!!!!!
>Please help me and, however, thanks for your interesting.
>Thanks once again.
>