create a function with Tdatabase

[Silvio.Falconi]

I would like to have a function that opens an archive and sets a series of indexes
I tried to do this function but it doesn't turn me at all I don't understand where I'm wrong

sample of Usage

oCustomers:Open_Db( "customer", , {FIRST,LAST} )
oCustomers:SetOrder( "FIRST" )
oCustomers:GoTop()

Code: Select all | Expand

FUNCTION Open_Db( cArchivio, aIdx )
   LOCAL cAlias
   LOCAL oDbf
   LOCAL i
   STATIC _Select_
   DEFAULT _Select_ := 0

   cAlias := "TD" + PADL( ++_Select_, 3, "0" )

   DbUseArea( .T. ,, cArchivio, cAlias, .T. )
   IF VALTYPE( aIdx ) == "A"
      FOR i := 1 TO LEN( aIdx )
         DBSETINDEX( aIdx[ i ] )
      NEXT
   ENDIF

   oDbf := TDatabase():Open(,cAlias)

RETURN oDbf

return me a message "TD0001.dbf not avaible"


then I tried with

Code: Select all | Expand

FUNCTION Open_Db( cArchivio, aIdx )
   LOCAL cAlias
   LOCAL oDbf
   LOCAL i
   STATIC _Select_
   DEFAULT _Select_ := 0

   oDbf := TDatabase():Open(,cArchivio)

   IF VALTYPE( aIdx ) == "A"
      FOR i := 1 TO LEN( aIdx )
         DBSETINDEX( aIdx[ i ] )
      NEXT
   ENDIF
RETURN oDbf
 

but make error because

Error description: Error DBCMD/2001 Workarea not in use: ORDLISTADD

Stack Calls
===========
Called from: => ORDLISTADD( 0 )
Called from: ../../../rddord.prg => DBSETINDEX( 0 )

what do you recommend?

[Antonio Linares]

Silvio,

Class TDataBase has a destructor method, so when the object gets out of scope then it gets called

change local oDbf into static oDbf (or keep it in an array) so the object is not destroyed

[nageswaragunupudi]

oDbf := TDatabase():Open(,cAlias)

This syntax is wrong. The DBF is already open.

Correct:

Code: Select all | Expand

oDbf := TDatabase():New( SELECT( cAlias ) )

[nageswaragunupudi]

Code: Select all | Expand

   oDbf := TDatabase():Open(,cArchivio)

   IF VALTYPE( aIdx ) == "A"
      FOR i := 1 TO LEN( aIdx )
         DBSETINDEX( aIdx[ i ] )
      NEXT
   ENDIF
 

Change this as:

Code: Select all | Expand

   oDbf := TDatabase():Open(,cArchivio)

   IF VALTYPE( aIdx ) == "A"
      oDbf:Exec( <||
         local i
         FOR i := 1 TO LEN( aIdx )
            DBSETINDEX( aIdx[ i ] )
         NEXT
         return nil
         > )
   ENDIF
 

[Silvio.Falconi]

thanks

[James Bott]

Sivio,

Maybe you didn't know that CDXs have always had the option to open all the indexes automatically when the DBF is opened. And as I understand it, NTXs can now do that also.

REQUEST DBFCDX
rddsetdefault( "DBFCDX" )
SET EXCLUSIVE OFF
SET(_SET_AUTOPEN, .T. )

[Silvio.Falconi]

Sivio,

Maybe you didn't know that CDXs have always had the option to open all the indexes automatically when the DBF is opened. And as I understand it, NTXs can now do that also.

REQUEST DBFCDX
rddsetdefault( "DBFCDX" )
SET EXCLUSIVE OFF
SET(_SET_AUTOPEN, .T. )

yes I knew it but it happens that in my application there is a function that does not have to load the indexes or in one of the functions that I have seen that does not load them all
As you well know in my old applications made for my school I had problems because sometimes the indexes were missing,
so not checking them first when opening the application seems to me a stretch because I am always afraid of not finding them in that folder

[James Bott]

yes I knew it but it happens that in my application there is a function that does not have to load the indexes or in one of the functions that I have seen that does not load them all

Hmm, I always open the indexes whether they are used or not. This simplifies coding doesn't have a downside that I can think of.

If you are using database objects, in order to not open the indexes sometimes, it would mean you would have to pass a parameter and when looking at the code you could never tell if the indexes were open or not.

Is there a reason you need them to NOT have the indexes open?