Mini database?

[Boris Nienke]

hi,

is there a simple "database"-solution available for the PocketPC (to be
used with C#.Net)?
Something like BTrieve, Paradox, DBase or even simpler... to let me write
some files with data on the desktop-PC and using them on the PPC without
converting them...

Any ideas?

Boris

 

[Ginny Caughey [MVP]]

Boris,

You can use DBF files on PocketPC devices with the Sequiter Software Codebase
library, but you would need to write PInvoke wrappers to use it from C#(unless
Sequiter already did that). Alternatively, you could use Sequiter's ActiveX
control with a 3rd party product from Odyssey Software that allows COM access
for .NetCF apps. I used Codebase with eVC++ apps, but I have abandoned it for
..NetCF apps. Instead, I create delimited text files on the desktop and parse
them into business classes on the device in C#. Very quick and easy.

That said, if/when there is the ability to create SqlServerCE files on the
desktop, that would probably be easiest of all. I have heard of a 3rd party
product that can create SqlCE files on the desktop, but I don't know of anybody
using it.

 

[C Enright]

Can you reveal the name of the 3rd party company with the
product that can create SqlCE files on the desktop?

Thanks..

 

[Ginny Caughey [MVP]]

I have seen it mentioned in a newsgroup message - I think it is a Dutch company.
But I think I also saw a message indicating that the link wasn't a good one.
Maybe somebody can help... Microsoft has also said that they are considering
providing this feature in a future version, but there has been no annoucement.

 

[Richard L Rosenheim]

Depending upon your exact requirements, keeping the information in a XML
formatted file might suit your needs.

Richard Rosenheim

 

[Steven Licciardi]

You could also just write your data to an xml file
(dset.WriteXML(filename)).

Steven

 

[Boris Nienke]

You can use DBF files on PocketPC devices with the Sequiter Software Codebase

i've search and found them - thank you for this hint but this one is a
very expensive solution ...

Instead, I create delimited text files on the desktop and parse
them into business classes on the device in C#. Very quick and easy.

because i'm very new to C# and .Net - could you please explain a bit
more in detail and maybe could you give me some time-meterings... how
long does it take to import - say - 2000 lines of 800 Bytes length..?

Do you read the whole data into memory at onces (very memory-consuming)?
or have you written access-code to read/write the lines you need to work
with?

thank you

Boris

 

[Boris Nienke]

i've worked with XML-Files on Desktop and i'm not very happy with it...

If you have a 5-10 MB XML-File it takes a long time until it is parsed
and it takes a huge amount of memory because the whole thing is build up
into a DOM-Model....

(i don't have a 100% idea about the ending file size of this project - i
just would like to make sure, that the file-size wouldn't limit me! It
may be the case that i like to export a lot of CAD Data ... and my
clients won't wait 30 Seks (or longer) for a file to be parsed... they
would like to start to work with the data)

If you know a way to work with XML-Files that are a bit larger than just
holding an adress or two (just kidding ) i would be glad to see it

Boris

 

[Ginny Caughey [MVP]]

Boris,

I agree that Sequiter is an expensive solution, especially since .NetCF gives
you so many others.

I don't have any 2000 line files to test with, but it would be meaningless
unless you and I had the same target hardware. I can tell you that parsing an
ASCII file is much faster than using an XML file. I do read in all my data at
once as my files usually have fewer than 100 lines, and that's acceptable. If
you want to make your own tests, use StreamReader.ReadLine to get each line from
the file, then String.Split to get an array of fields from the line. Finally,
use members of the Convert class to convert non-string data to the form you
want.

Or as a third choice, maybe you could create your SQLCE file in the emulator and
copy that to the device.

 

[Steve Wilkinson]

The company that offers a utility to generate sdf files on the desktop is
called HOB, it is a Danish company.
The website is www.hob.dk.

Their utility builds sdf files from 2 xml files, 1 containing the DB schema
information and 1 containing the actual data.

We did some initial tests and they looked very promising, but we are waiting
to see if Microsoft pull their finger out and give us the ability to create
sdf files from the full .NET Framework.

Steve

 

[Richard L Rosenheim]

As I stated originally, it depends upon your exact requirements. 5-10MB
data files are probably not best suited as XML file. And, of course, it
also depends on how you are using the data.

If you just want to sequentially read the file and extract some of the data,
then you may also wish to look into using XMLTextReader.

Richard Rosenheim