Saturday, October 29, 2005
Friday, October 28, 2005
Just to remind everyone of the Tools support matrix. Actually, this is a funny way of bookmarking this page, huh?
It reminds us that we have to keep all tools under our belt, from eVC3 to VS 2005 (if we are targetting all sorts of devices, that is...).
Waiter! Another Pilsener, please!
Saturday, October 22, 2005
Most databases that use IDENTITY columns will do so for primary key or index support, meaning that these values are generally laid out in row creation order. For a table with few deletions, it is very likely that you can find large continuous ranges for which you can let the IDENTITY column do its job - generate the next value.
I write this after finishing my first tests on Data Port Wizard and a new version of the device component. For "well behaved" databases such as the Northwind sample, the code only needs to change the IDENTITY seed twice per table and performance does not seem to be an issue. On databases with sparse tables (where the number of gaps in IDENTITY values is large) performance may be a concern because the base table cursor must be closed before the seed is changed, and reopen again to continue data insertion.
Friday, October 21, 2005
From: Windows Mobile Update
Subject: ActiveSync 4.0 Issue Alert
Microsoft wants to alert you to an issue regarding ActiveSync 4.0 and the immediate steps the company is taking to resolve it and meet customer needs.
Specifically, some users of ActiveSync® 4.0 have reported challenges when using the USB connection of their personal computer to connect to a device with Windows Mobile 5.0. In many cases, these challenges are likely caused by interoperability with desktop firewall applications or applications that manage network traffic. These applications appear to conflict with the TCP traffic between a device and the PC.
An update for ActiveSync is scheduled to be available in late November, but customers may also resolve the issue manually immediately by visiting visiting http://www.microsoft.com/windowsmobile.
This issue only affects people with new devices just coming to market and running Windows Mobile 5.0 software, and only when synchronizing directly to a PC (wireless synchronization via Bluetooth, infra-red or directly to a server or other services are not affected).
- In the U.S., these devices include the Sprint PPC-6700, iMate JasJar, iMate KJam, iMate SP5, Dell Axim X51v,HP iPAQ rx1955 Pocket PC, HP iPAQ hx2495 Pocket PC, and the HP hx2795 Pocket PC.
- In Europe, these devices include the Orange SPV M5000, iMate JasJar, iMate K-Jam, T-Mobile Vario, T-Mobile MDA Pro, O2 XDA Exec, O2 XDA Mini S, O2 XDA Phone, FSC Pocket LOOX N500, Dell Axim X51, Dell Axim X51v, HP PPC series (rx1950, hx2190, hx2490, hx2790).
- In Asia, the devices affected are the iMate JasJar, iMate KJam, iMate SP5 and iMate SP5m.
Microsoft is committed to solving this issue for its customers and its partners.
For more information, please contact the Windows Mobile PR team at 425.452.5400 or firstname.lastname@example.org.
Sunday, October 16, 2005
The answer? OLE DB, of course!
Saturday, October 15, 2005
Now let's wait for some good news on the IDENTITY column issue.
Wednesday, October 12, 2005
SQL CE 2.0 allowed consumers to write on IDENTITY columns, a feature that enables copying desktop databases. The table is created on the device with the IDENTITY column set at the given seed and increment. When copying the table data, the column values are forced (the OLE DB provider complains mildly) and the resulting table behaves exactly like the source one. Interestingly, both Jet and SQL Server allow this so why wouldn't SQL Mobile allow it as well?
Monday, October 10, 2005
Note: If you are developing against SQL Mobile, you might want to install the error messages DLL - sqlceer30EN.dll.
Sunday, October 09, 2005
First, the whole project was ported from eVC3 to eVC4. This was not a strict requirement, but since I was targeting a Pocket PC 2003 device I decided to do so. The result was interesting because I ended up dropping some dead code that still hangs around on the SQL CE 2.0 version... Now I have a smaller DLL (87 KB).
When porting to eVC4, I had to drop Giuseppe Govi's STL port and use the one that ships with the Pocket PC 2003 SDK. Apparently the old STL code will create a number of compile-time conflicts with the XML headers...
After changing a few constants and applying the small correction I mentioned on my last post, the code started to work - in less than one hour (most of this time was spent with the eVC3 to eVC4 migration).
The SQL Mobile component can be downloded from here. Please note that this will retain a Beta status while SQL Mobile is also a Beta product. To install it, just copy it to your device's \Windows directory and you are done.
Saturday, October 08, 2005
Bookmarks are now unsigned integers (DBTYPE_UI4) when they were integers in SQL CE 2.0.
Another interesting difference occurs when you open a table with an index. With SQL CE 2.0, using an empty string for the index name would be interpreted as no index selection. No so with SQL Mobile - an empty string seems to be a valid index name and the table will refuse to open. Here's some code I had to change in my previously published CIndexTable class template (in bold):
if(szIndexName && wcslen(szIndexName))
idIndex.eKind = DBKIND_NAME;
idIndex.uName.pwszName = (LPOLESTR)T2COLE(szIndexName);
pIndex = &idIndex;
I am testing the whole code against SQL Mobile and will post my findings as they come up.
Tuesday, October 04, 2005
Jet lag was one of my biggest problems. It was so big that when I met Alex Feinman, I thought I was talking to Andy Wigley and complimented him on his book... Foot: meet mouth! (Sorry Alex!)