PC Toledo

Código: Selecionar todos

use ...
set filter to ...
COUNT to nNum

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local nRecs := 0
Use ...
Set Filter To ...
Alias->( DBEVAL( { || nRecs++ } ) )

*-- Onde nRecs vai ter o total de Registros da área Filtrada.

Código: Selecionar todos

	
FUNCTION SPEEDFLT( expflt )
/*
    Parameter expflt - an expression, which execution we should
    optimize, for instance, "DNAKL=CTOD("01/01/96").AND.SUMMA>1000000... "
*/
LOCAL rez  := .F.,;  // a variable to keep a result of analysis
      iord := 0,  ;  // index counter
      ielem, elemf, ellen, elemzn, poz, poz1, poz2, poz3, exptmp, expind
 
PUBLIC stseek,;      // a key to search the first record
       stusl         // an expression for <i>DO WHILE</i> cycle
 
   STORE "" TO stseek, stusl
 
   // Beginning of main cycle - scan and analysis all opened indexes 
   DO WHILE !rez
      iord++         // Increment index counter
                     // take a key expression
      expind := Upper( Ordkey( iord ) )
 
      IF Empty( expind )   // Exit, if there no more indexes
         EXIT
      ELSE                 // otherwise - we begin analysis of a key expression
 
/*
      We look for expression items, divided by the sign "+".
      For example, in the expression "DTOS(DNAKL) + NNAKL + STR(CENA,11,2)"
      we have three items:  DTOS(DNAKL), NNAKL and STR(CENA,11,2)
*/
 
      DO WHILE !Empty( expind )
 
        // Look for the next item
        poz := At( "+",expind )
        IF poz != 0
           ielem := Left( expind,poz-1 )
           poz ++
           expind := Substr( expind,poz )
        ELSE
          ielem := expind
          expind := ""
        ENDIF
 
        // Then we check, is the item a function ( by presence of "("
        // or it is only a field name
        poz1 := At( "(", ielem )
 
        IF poz1 == 0
           elemf := ielem // it is a fieldname
        ELSE
           // if we found opening bracket "(", we cut
           // the field name from the item, supposing that it begins right after
           // this parentheses and ends with comma "," or closing bracket ")"
           elemf := Substr( ielem,poz1+1 )
           poz2  := At( ",",elemf )
 
           IF poz2 == 0
             poz2 := At( ")", elemf )
           ENDIF
           IF poz2 != 0
              elemf := Left( elemf,poz2-1 )
           ENDIF
        ENDIF
 
        ellen := Len( elemf )   // Get length of a field name
 
        // Now search this fieldname in 'expflt'
        poz2 := At( elemf, Upper(expflt) )
 
        IF poz2 > 0 .AND. Substr( expflt,poz2+ellen,1 ) == "="
           // If it is found, and it is followed by the "="
           IF At( elemf, Upper( Substr( expflt,poz2+ellen+1 ) ) ) == 0
              /*
               and this field name is not met in the expression anymore
               ( it is needed to exclude expressions with .OR.
               on this field ) to be sure that current key expression allows
               to optimize a performing of an expression.
              */
              rez := .T.
              /*
               Now continue an analysis to build stseek and stusl.
               For this purpose we extract the required value of a field
               from an expression.
               We consider that this value must be in "expflt" immediately
               after the "=", and will be completed by a newline
               or a dot "." ( if there are .AND or .OR. )
              */
              elemzn := Substr( expflt, poz2+ellen+1 )
              poz2 := At( ".", elemzn )
              IF poz2!=0 .AND. Isdigit( Substr( elemzn,poz2+1 ) )
                 poz3 := At(".",substr( elemzn,poz2+1 ) )
                 poz2 := poz2 + Iif( poz3==0, 999, poz3-1 )
              ENDIF
 
              elemzn := Substr( elemzn, 1, Iif(poz2==0,999,poz2-1) )
              // Now build 'stusl'
              stusl += Iif( Empty( stusl ), "", ".AND." ) + elemf + "=" + elemzn
              // and 'stseek'. For this we substitute found line with value
              // fields (elemzn) in key expression item instead of a field name,
              // compute a tin expression and add to stseek!
              exptmp := Stuff( ielem, poz1+1, ellen, elemzn )
              stseek := stseek + &exptmp
           ENDIF
        ENDIF
        IF !( elemf $ stusl )
           // If next element not suitable for optimization,
           // stop an analysis of current key expression.
           EXIT
        ENDIF
      ENDDO
    ENDIF
  ENDDO
 
  IF rez
     // If suitable index is found, set it as current
     Ordsetfocus( iord )
  ENDIF
 
RETURN rez

Código: Selecionar todos

	
FUNCTION FINDREC( expfnd ) // expfnd - condition for searching
LOCAL rez := .F.
 
   IF Speedflt( expfnd )   // If the request is optimized,
      Dbseek( stseek )     // search first record, partly satisfying
   ELSE                    // the condition, otherwise -
      GO TOP               // go to the beginning of a file
      stusl := ".T."
   ENDIF
   rez := .F.
   DO WHILE !Eof() .AND. &stusl
      IF &expfnd
         rez := .T // Suit record is found!
         EXIT
      ENDIF
      // Here you can insert something to animate the process of searching
      SKIP
   ENDDO
RETURN rez

Código: Selecionar todos

Select dbf
DbSetOrder(1)
DbGoTop()
OrdScope( 0, filtro )
OrdScope( 1, filtro )
DbGoTop()

Count to nn

dd = OrdKeyCount()

nn retorna 2
dd retorna 4 (ha dois registros deletados)

Código: Selecionar todos

In both cases it's the same reason: 
   set deleted on 
ordkeycount() returns number of keys in index regardless of SET DELETE ON 
flag. If you remove this command from your example then you will access 
deleted records in your skip loop. 

best regards, 
Przemek