OT macro operator

OT macro operator

Postby Detlef Hoefner » Wed Oct 24, 2007 10:35 am

Hi All,

a very stupid question but it's driving me nuts.
I want to update a field in a dbf.
The field name is defined in an array.

Code: Select all  Expand view
#define DB_DBF 1
#define DB_FLD 2

LOCAL aDbf := {;
            { "dbf_1", "fiel_name_1" },;
            { "dbf_2", "fiel_name_2" },;
             ...
            { "dbf_n", "fiel_name_n" },;
    }

I can do
Code: Select all  Expand view
use ( aDbf[n][DB_DBF] ) shared alias wrk new

But i can not
Code: Select all  Expand view
wrk->&aDbf[n][DB_FLD] := uVal


I tried several variations. Either i get "invalid lvalue" at compile time or "&syntax error" at runtime.

So many years clippering but stumbling over such stupidity.
Sorry for bothering you. :oops:

Regards,
Detlef
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Re: OT macro operator

Postby Richard Chidiak » Wed Oct 24, 2007 11:32 am

Detlef,

I remember some time ago having a similar problem

This is how i got it working

DT := "CLIENT" + ALLTRIM(SUBS(TABVAR[15][J],63,6))
REPLACE (MYFILE)->&DT WITH .....

HTH

Richard
http://www.cbati.com

Uestudio
Fwh 13.05 Harbour 3.2 MSVC 2013
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Postby Detlef Hoefner » Wed Oct 24, 2007 11:44 am

Richard,

thanks a lot for your answer.
I just found an other workaround which i will also show, allthough it is dangerous code if the field doesn' t exist.

Code: Select all  Expand view
wrk->( fieldput( fieldpos( aDbf[ n ][ DB_FLD ] ), uVal ) )


But thanks again, Richard.
Regards,
Detlef
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Postby nageswaragunupudi » Wed Oct 24, 2007 12:00 pm

This works:

Code: Select all  Expand view
wrk->&( aDbf[n][DB_FLD] ) := uVal


Anyway my personal preference in such cases is fieldput and fieldpos. I try to avoid macros. Again its a matter of choice.
Regards

G. N. Rao.
Hyderabad, India
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Postby Detlef Hoefner » Wed Oct 24, 2007 12:14 pm

NageswaraRao,

many thanks for your answer.
As you i always avoided the use of the macro operator.
But therefor i have a poor knowledge about it.

Thanks again for your hint.

Regards,
Detlef
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Postby Barry O'Brien » Wed Oct 24, 2007 1:49 pm

Hi Detlef,

I had a similar problem just yesterday trying to do:

Code: Select all  Expand view
cDBField := "ACNT_NBR"
REPLACE PAYMENT->&cDBField WITH cValue


This was causing the "&syntax error" you mentioned.

I fixed it by doing the following:

Code: Select all  Expand view
cDBField := "PAYMENT->ACNT_NBR"
REPLACE &cDBField WITH cValue


Not sure if this will help in your circumstances but it worked for me.

Kind regards,

Barry
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Postby Detlef Hoefner » Wed Oct 24, 2007 2:12 pm

Thanks, Barry

the response in this forum is unbelievable.

Regards,
Detlef
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Postby James Bott » Thu Oct 25, 2007 1:28 am

Detlef,

Aren't you using TData? Did you know that the data is already buffered?

In TData the fieldnames are stored in aFldnames.

Perhaps if you explain what you are trying to do, I can help with a TData solution.

James
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Postby Detlef Hoefner » Thu Oct 25, 2007 8:06 am

James,

thanks for your kind offer.
But my problem concerned a mere MS DOS program where i had dbf and field names in an array and had to update those fields in a loop from each dbf.

Thanks and regards,
Detlef
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Postby FiveWiDi » Thu Oct 25, 2007 10:59 am

James Bott wrote:Detlef,

Aren't you using TData? Did you know that the data is already buffered?

In TData the fieldnames are stored in aFldnames.

Perhaps if you explain what you are trying to do, I can help with a TData solution.

James


Where is Tdata class?

Thanks,
Carlos G.
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Postby James Bott » Thu Oct 25, 2007 9:05 pm

>Where is Tdata class?

TData is a commercial product I developed. You can read more about it and download a demo on my website.

http://ourworld.compuserve.com/homepage ... rogram.htm

James
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