DBF TEMPORARY

[AntoninoP]

HB_DBCreateTemp( cAlias, aStruct, cRDD ) --> lSuccess
... use cAlias like any other alias
CLOSE cAlias at the end

Hi,
I am trying to substitute temporary database file with this, how can I associate an area to it?
Regards,
Antonino

[nageswaragunupudi]

The first parameter itself is an Alias ( not a file name ) and this Alias is the workarea.

Example:
cAlias := cGetNewAlias()
if HB_DbCreateTemp( cAlias, aStruct, cRDD )
// do work with cAlias
// ? SELECT( cArea ) is the number of the work area.
CLOSE cAlias
endif

[fp]

Hb_DbCreateTemp is a really good feature. I did not know this before. Is there also the possibility to create an index file and open?

[nageswaragunupudi]

You can do all operations like a normal DBF.
This is exclusive open.
If the PC has more RAM it is lightning fast.

[James Bott]

Since there seems to be a lot of interest in temporary DBFs, I am curious how others are using them?

I don't remember using one in a very long time, so maybe I am missing out on something.

Regards,
James

[Biel EA6DD]

The first parameter itself is an Alias ( not a file name ) and this Alias is the workarea.

Example:
cAlias := cGetNewAlias()
if HB_DbCreateTemp( cAlias, aStruct, cRDD )
// do work with cAlias
// ? SELECT( cArea ) is the number of the work area.
CLOSE cAlias
endif

The Temporary File is created on the hard disk? or in memory?

[James Bott]

Biel,

The Temporary File is created on the hard disk? or in memory?

In memory.

James

[Biel EA6DD]

Biel,

The Temporary File is created on the hard disk? or in memory?

In memory.

James

Thanks James, what is confusing me is the 3st parameter cRDD.

I never used but like mentioned Carles there are Memory RDD like ArrayRDD and HB_MEMIO, if not misunderstand hb_DbCreateTemp will use one of those RDD.

[James Bott]

Biel,

I never used but like mentioned Cales there are Memory RDD like ArrayRDD and HB_MEMIO, if not misunderstand hb_DbCreateTemp will use one of those RDD.

Agreed, it is not clear. Also, does this work only with Harbour or also with xHarbour?

It would be helpful if someone would post a small working example. Anyone?

James

[Euclides]

Hi, this is a very small example:

Code: Select all

#include "fivewin.ch"

Function Main()
local cArq:="TST"
local aStruct:={{ "VEND", "C", 14, 0 },;
                { "NOMV", "C", 40, 0 },;
                { "FILX", "C", 02, 0 } }

   use CUSTOMER     //  Just to see how DBCreateTemp selects areas

   HB_DBCreateTemp(cArq, aStruct)
*
   for nY=1 to 99
       dbappend()
       TST->FILX := str(100-nY,2)
       TST->NOMV := replicate(TST->FILX,10)
       TST->VEND := str(nY,4)
   next
   index on FILX+NOMV+VEND to (cArq)
   browse( "Select:"+str(select(),3) )  //  Show "Select: 2"
   CLOSE
return nil
 

Regards, Euclides

[Marc Vanzegbroeck]

Hi,

It seems that HB_DBCreateTemp() doesn't exist in xharbour..

[James Bott]

Euclides,

Thanks much for the example. I have it working. Do you know what RDD the function defaults to?

Marc,

I am running it successfully with xHarbour (ver 1.2.3). I believe this is the latest version and it is from 2013. Is yours older?

James

[nageswaragunupudi]

Defaults to the default RDD of the application.
But I always used "DBFCDX" as the 3rd parameter.
Works with Harbour and xHarbour.

[Marc Vanzegbroeck]

Marc,

I am running it successfully with xHarbour (ver 1.2.3). I believe this is the latest version and it is from 2013. Is yours older?

James

James,

Indeed, I use an older version of xharbour.

Mobiel verstuurd via Tapatalk

[AntoninoP]

I am not able to use them, in my program I have all area in numbers.
look this code:

Code: Select all

proc main()
   local cArq:="test",i
   LOCAL t1 := hb_milliSeconds(), t2
   
   FERASE( cArq+".dbf" ) // 
   dbSelectArea(2)
   dbCreate( cArq, { { "ITEM", "N", 10, 2 },{ "RAND", "N", 10, 2 },{ "TESTO", "C", 10, 0 } } )
   USE (cArq)
   dbSelectArea(1)
   
   t2 := hb_milliSeconds()
   ? "Database creation: " + str(t2-t1) + "msec"
   t1 := t2
   
   for i:=1 to 100000 
      (2)->(dbAppend())
      (2)->ITEM := i / 100
      (2)->RAND = hb_Random(100)
      (2)->TESTO = hb_randStr(10)
   next
   
   t2 := hb_milliSeconds()
   ? "100.000 fields in " + str(t2-t1) + "msec"
   t1 := t2

   dbSelectArea(2)
   INDEX ON STR(FIELD->RAND,6,2)+STR(FIELD->ITEM,6,2) TAG "ITEST"
   
   OrdSetFocus( "ITEST" )
   DBGOTOP()

   t2 := hb_milliSeconds()
   ? "index in " + str(t2-t1) + "msec"
   t1 := t2
   
   WAIT "Press a key..." 
   browse(2)
   close
return

Our program is like this, but spread in about ten source files.

I tried to convert it with HB_DBCreateTemp, but without success, if I try it with "ARRAYRDD" is slower.