Windows CE - Database - vb.net

Question

I need to setup an application to scan a barcode from a packing slip and the associated fulfillment items on a windows CE 5.0 device and update the inventory on the server. I'm using VB.NET. However, what is the best way to interact with the database? Integration Services, ADO.NET, RDA... etc... it's a bit overwhelming trying to figure out what I should use to interact with the database. It's currently an Access database, but I imagine I'm probably going to need to migrate it to SQL Server or SQL Server Express.
I'd also need to print the packing slip to a network printer from the device. Is there any way to do this?

Answer 1

Sql CE is an excellent choice if your devices have to function for stretches in a disconnected state (i.e. not connected to the server). If you do use Sql CE, however, I strongly recommend not using RDA to persist local changes back to the server database (see this answer). In any event, RDA merge replication would require your server database to be Sql Server.
If your devices are always connected to the server through a wireless network, then you do not need a local database on the devices at all. Your devices can upload and download data through ASP.Net web services running on the server. Using DataSets for this communication is a good choice, since they are essentially database-agnostic (and thus your PDA code won't particularly care what database you're using on the server).
The web service approach will also let you handle the printing requirement. The PDA would send the relevant information to a web service method, which would then handle printing to the network printer.

Answer 2

My recommendation is to use SQL Server Compact edition (http://www.microsoft.com/Sqlserver/2008/en/us/compact.aspx) for storage engine, and ADO.net implementation of SqlCe in System.Data.SqlServerCe namespace (http://msdn.microsoft.com/en-us/library/system.data.sqlserverce.aspx) for code interaction. They are very well integrated with Visual Studio 2008, including designer support of strong-type dataset and run-time examination of data content on device etc.
No idea about the printing.

Answer 3

In all today scenarios, I would recommend using SQLite. It is the most used database today. Don't bind yourself to an database ecosystem. Just go here and search for "Precompiled Binaries for Windows CE (.NET Compact Framework)". Then you have a SQLite.Interop.*.dll and the System.Data.SQLite.dll. The SQLite.Interop.*.dll has to be placed and deployed besides your EXE file. The System.Data.SQLite.dll is the managed wrapper, that you have to reference in your project. Example: Create SQLite Database and table
SQL Server Compact is not compatible to most mobile platforms like iOS, Android and so on. Microsofts support for old target platforms is poor, leaving Windows CE with only SQL Server Compact 3.5 SP2 where you don't have some essential SQL functions like "LIMIT". Databases generated on the Desktop OS (> Windows XP) will also need to be converted on the device (long delay, when you first open the database), because MS is using different code pages on desktop and Windows CE.
This is Microsofts statement about RDA:
Because of design limitations, remote data access (RDA) will be removed in a future release. If you are currently using RDA, you should consider transitioning to Microsoft Synchronization Services for ADO.NET. If you were planning to use RDA in a new application, you should instead consider merge replication or Sync Services. Note that Sync Services is currently available only for the Windows Desktop Operating System.
Best way to interact with the database is just build the database on the server, compress it als deflate (available under both Desktop and Compact via System.IO.Compression) and send it to the device in whole. Plain and stupid. Most devices have poor import performance, so doing the import locally may take too much time, even if you have a fancy sync framework.
To transfer the database you can use a WCF service or just any web server using a HTTPS GET. Like so:
// ppp_peer is in most cases the active sync connected pc
string url = #"https://ppp_peer/export/database.db.gz";
string html = string.Empty;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
using (Stream stream = response.GetResponseStream())
using (FileStream fs = new FileStream(stream))
{
// Decompress your database here
}
To ORM your POCO objects just use something like https://bitbucket.org/twincoders/sqlite-net-extensions
However, if you have WLAN access everywhere, I would consider writing a browser application and using the mobile browser together with a web server for your needs. Just keep in mind, that Windows CE 5 based devices don't come with HTML 5 support out of the box. If you have a choice consider switching to a Android based device.