Subject Re: using a query as variable : question does anyone some opinions From Dirk C <dirk@C.com> Date Fri, 31 May 2024 23:02:20 +0200 Newsgroups dbase.getting-started   Mervyn,   thanks for more insight into   your suggestion form.processRow() : such a function gave me already   more inspiration semi automate this programm, just think about it   the difference between procedure and function ( altough by dBase the same) is a bit confused have a nice weekend Dirk, Op 31/05/2024 om 17:14 schreef Mervyn Bick: > On 2024/05/30 21:00, Dirk C wrote: >> Hello >> the following is working, but like to have som opinion about >> >> using thh query build on form or create a variable of a query >> >> both are working, but i am wondering if to catch the variable is more >> stable > > One of the Golden Rules of programing is "If it works, it's not wrong.". > :-) There may, however, be a simpler, better, faster, more elegant (take > your pick :-) ) way of doing it. > > The main reason for saving a query (or any object for that matter) to a > memory variable is to save typing later in your source code.  It makes > absolutely no difference to dBASE whether you use > >       q_Cross = this.parent.vraagbak_artCon >       q_cross.active = false >       q_cross.sql = form.vraagbak_zoek >       q_Cross.active = true > or >       form.vraagbak_artCon.active = false >       form.vraagbak_artCon.sql = form.vraagbak_zoek >       form.vraagbak_artCon.active = true > > All programmers develop a style so this is purely a personal opinion but > I don't like changing a query's sql property in a program.  While it is > possible with a standard query, keep in mind that this causes problems > with an ADOquery.  Instead of using applyLocate() I prefer to use a > parameter driven query. > > Back in the early days of dBASE, FUNCTIONs returned a value and > PROCEDUREs didn't.  Over time the distinction has been removed and > PROCEDURE as defining command has fallen into disuse.  As function > knop_zoek_onclick() doesn't return a value it is actually a procedure. > As a procedure it actually needs some code to deal with success or > failure to find a matching record otherwise your program is just waiting > for further input from the user.  Either set the cursor ready to receive > a new search value or use the selected record to do something. > > In function knop_zoek_onclick() there is no need for > q_Cross.rowset.beginlocate() which is used to allow a datalinked > entryfield to be used to input a search value. > > Instead of nesting if...else...endif constructs as you have done, an > if...elseif...else...endif construct (which works exactly like DO CASE) > is a better option in this case as this terminates immediately a test > returns true. > > If you use similar code multiple times in a function or procedure it can > usually be factored out.  This will cut down on the size of the code and > will usually make it easier to follow. > > A reworked version of function knop_zoek_onClick() follows.  It hasn't > been tested so there may be typos.  I'm not suggesting that you change > your existing working code but this is an approach to keep in mind for > "next time". > > function knop_zoek_onclick() >     local c_Ref1, c_Waarde1, q_Cross, c_Ref2, c_Ref3,bFound >     c_Waarde1 = this.parent.veld_Zoek.value >     q_Cross = this.parent.vraagbak_artCon >     q_Cross.rowset.locateOptions = 0 >     c_Ref1 = "conartikel1 ='"+c_Waarde1+"'" >     c_Ref2  = "conartikel2 ='"+c_Waarde1+"'" >     c_Ref3  = "conartikel3 ='"+c_Waarde1+"'" > //   q_cross.active = false > //   q_cross.sql = form.vraagbak_zoek > //   q_Cross.active = true >     if empty(c_waarde1) >        bFound = false >        msgBox("data ingeven", "***** bci dataverwerking *****", 48) >          //No search value.  Remaining tests will be skipped >     elseif  q_Cross.rowset.Applylocate(c_Ref1) = true >          bFound = true >          //c_Ref1 found so rowpointer on record. Remaining tests will be > skipped >         //if c_Ref1 not found, try c_Ref2 >     elseif  q_Cross.rowset.Applylocate(c_Ref2) = true >        bFound = true >     elseif  q_Cross.rowset.Applylocate(c_Ref3) = true >        bFound = true >     else >        bFound = false >        msgbox("geen data gevonden vir "+cWaarde1) >        form.veld_Zoek.value = ''  //Remove previous value >        form.veld_Zoek.setFocus()   // Ready to accept a new search value >     endif >     if bFound = true  //A matching row was found. >        form.processRow()  //Code to continue the program instead of >                           //waiting for the user to press another button. >     endif >     return > > > Mervyn.