[Lazarus] DBGrid columns shrunk to fit data

[Jesus Reyes]

--- El jue 18-jun-09, waldo kitty <wkitty42 at windstream.net> escribió:

> De:: waldo kitty <wkitty42 at windstream.net>
> Asunto: Re: [Lazarus] DBGrid columns shrunk to fit data
> A: "Lazarus mailing list" <lazarus at lists.lazarus.freepascal.org>
> Fecha: jueves 18 de junio de 2009, 19:43
> Luca Olivetti wrote:
> > En/na Graeme Geldenhuys ha escrit:
> >> Graeme Geldenhuys wrote:
> >>> Is there an option for the DBGrid to
> automatically resize its columns to
> >>> fit the data?
> >> 
> >> 
> >> Anybody know if TDBGrid can do this? If so, what
> properties need to be set?
> >> 
> >> Here is a bug report regarding this issue. The
> report also contains two
> >> comparison images showing the difference:
> FlameRobin vs LazDataDesktop
> >> executing the exact same query and the default
> result data grid generated.
> > 
> > TRxDBGrid can do it, however (and obviously) it has to
> iterate through all the records to find the longest one.
> 
> hunh? why iterate thru? doesn't it already have to process
> each row when they come in from the server? that would be
> the time and place to do this width setting, in my old
> school procedural mindset...

The grid only knows about the records that fit in its rectangular area, for this limited set of records the grid could autosize columns without performing additional fetches. 

AFAIR the dataset caches only 10 records by default. Retrieving all records from dataset works only nice for some dbengine-local/remote combinations, nobody likes to wait too much while the grid retrievs thoudsand o millions of records from remote server just to find what is the best column size. Moreover, some databases provide cursor with forward only transversal even when grid could retrieve everything it doesn't have functionality to cache records locally. So the final decision need to be made by the programmer through options.

So what are the options?, one could ask the grid to do autosizing with it's limited set of records, another, it could use first-next to browse all records, it could do the later using some amount of records only, etc. Once autosizing is made should it try again as new records become available until eof, ....

ideas?

btw, I also found annoying to have so big column sizes, it seemed to me that previoulsy it didn't do this, but I know it wasn't done intentionally in the grid :)

Jesus Reyes A.


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