🚀 go-pugleaf

In article <36a771af.9942236@forums.borland.com>, Thomas Preston politely 
paraphrased ...
> I was encountering an error in a complex filter string that had the
> format . . .
> 
> form.rowset1.filter=(this=that OR that=this) AND (thisthing=thatthing
> OR thatthing=thisthing) AND (a=1 OR a=2 OR b=1 OR b=2 OR c=1 OR c=2 OR
> d=1 OR d=2 OR e=1 OR e=2 OR f=1 OR f=2 OR g=1 OR g=2 OR h=1 OR h=2 OR
> i=1 OR i=2) AND (theother=this OR this=theother)
> 
> The problem was in the longest segment (a=1 . . .).  I think that
> there must be a limit to the number of arguments contained within
> parens.  Anyway . . . I resolved the issue by modifying the form
> (splitting the controls).
> 
> In other words . . . WHEN ALL ELSE FAILS, MANIPULATE THE DATA.
> 
I just made some tests and my conclusion is that 16 conditions is the 
max. The length of the filter string doesn't matter. Here's my short 
testprogram.


close all
erase longfilter.dbf

if not file("longfilter.dbf")
  cCommand=[CREATE TABLE "LONGFILTER.DBF" (]
  for n= 1 to 50
   cCommand+=[ ALONGDBFFIELD]+ltrim(str(n))+[ char(1)]
   if n<50
    cCommand+=[,]
   else
       cCommand+=[)]
   endif
  next
 &cCommand.
 use longfilter
 generate 10
 use
endif
local q
q=new query()
q.sql=[select * from "longfilter.dbf"]
q.active=true
  cFilter=""
  nFields=16 // change to 17 and it will error out
  for n= 1 to nfields
   cFilter+=[ ALONGDBFFIELD]+ltrim(str(n))+[ ='A' ]
   if n<nfields
    cFilter+=[ AND ]
   endif
  next
 msgbox(cfilter,"Filter length:"+str(len(cFilter))+;
 " Conditions:"+str(nFields))

q.rowset.filter="&cFilter."

q.active=false
/-----------

OTOH when using ..WHERE..it works.


local q
q=new query()
  cSQL=[SELECT * FROM "LONGFILTER.DBF" WHERE ]
  nFields=50
  for n= 1 to nfields
   Csql+=[ ALONGDBFFIELD]+ltrim(str(n))+[ ='A' ]
   if n<nfields
    cSQL+=[ AND ]
   endif
  next
 msgbox(cSQL)
q.sql=cSQL
q.active=true

q.active=false
return





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Romain Strieff [TeamB]
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