I have tried to use DataSnap on Advantage Database but I cannot update my data. I use TAdsQuery on datasnap server and return the query to client and link it with TDataSetProvider.
I traced into and saw Delphi applies updates using TSQLConnection not my TAdsConnection I have in server side.
Any idea?
I wrote a white paper for Advantage (Sybase) to show how Advantage Database Server and Delphi's DataSnap work just fine. I'm not sure what/where your problem is exactly.
Check out http://www.drbob42.com/examines/examinD8.htm for the DataSnap Server and http://www.drbob42.com/examines/examinD9.htm for the client.
The DataSnap client uses a TSQLConnection to talk to the DataSnap Server. The DataSnap Server uses a TAdsConnection to talk to the Advantage Database Server. The client never has any "knowledge" about the actual database; that's what the server is for.
Groetjes, Bob Swart
Related
In my server application I have some datasets, connected with TDataSetProvider
In client app, I use TClientDataSet
On some server methods, I changing SQL property of queries, and reloading data in server module.
But nothing changes on client app.
How to solve it in best way?
Thanks.
Is it possible to convert Delphi SoapServer application to use TCP/IP?
From your comment to your question it sounds like you are looking to get rid of SOAP, and use something else to communicatie over a TCP/IP connection.
The question one could ask is why do you want to convert to non-SOAP comm over TCP/IP?
But the answer to whether it is possible is: of course this is possible, there are many application servers using TCP/IP for communication without using SOAP as their communication's protocol.
You will need some kind of protocol for communication between server and clients. You could roll your own, but doing what SOAP is doing for you now: receiving and responding to commands from clients (or method invocation) and marshalling data/objects between server and clients is not a trivial task.
So I'd suggest you have a look at other remoting libraries for client/server communication, such as:
Remobjects: http://www.remobjects.com/
kbmMW: http://components4developers.com/
As others have said, SOAP is just XML on http/https, and usually does already use TCP.
That said, you could simply treat it as raw socket data or http data. i.e. you could make a client that just uses http POST to send a string to the server. The string would contain an XML SOAP request, and would be treated by the server as if it were SOAP. Likewise, you could build the server in a non-SOAP fashion, just accepting XML and returning XML, and the client wouldn't know the difference.
You can use Fiddler2 to play with this. You can build requests and send them via HTTP Post. The server has no idea that you're not a SOAP client.
Chris
If you're talking about pre-Delphi
2009 DataSnap, meaning COM based
DataSnap, then you have to use a third
layer utility to do the communication.
That utility named sockets.exe is
included with Delphi, and is in the
same dir as Delphi (Program
Files\\\\bin
If it is Delphi 2009 or better, then
DataSnap has built-in TCP/IP
functionality. You use
TDSTCPServerTransporter component.
Update: Ups! for some reason I did read DataSnap SoapServer (wich neither exists, but I did think of Soap Connection).
A Soap Server Application needs the "server" part, meaning a web server. SOAP is an technologie that runs over HTTP protocol, so I don't think it could be "converted".
DataSnap could do the job, or Indy TIdTCPServer or some of the derived classes.
What are the advantages in using DataSnap compared to writing a
soapserver application.
I know Datasnap can use TCP/IP instead of soap.
Regards
Sandeep
With DataSnap you can export any number of datasets, and server methods, without the need of manually serialize them, adding built-in funcionality of parameterized querys, in wich value of the parameters are defined from the client. On the client side, you just have to connect to the remote datasource or methods to any data aware control using a ClientDataSet as data cache, with automatic update command generation.
SOAP is a more raw way to do everything, and IMHO the only thing you gain using WS is compatibility. If you are not using Delphi on the client side, then that is the way to go.
DataSnap is a remoting technology which directly supports Delphi database architecture. Actually DataSnap supports SOAP too - check the TSoapConnection component (but of course a plain SOAP server is not a Datasnap server also).
Be aware that currently exists two Datasnap implementation. The "older" one using DCOM/SOAP and a "newer", dbExpress-based one, supporting TCP and HTTP/REST.
At the MSDN website it says, "Connecting to SQL Azure by using OLE DB is not supported."
There are other places on the web where folks report that it works fine for them after tweaking the server name in the connection string, such as here and here. Even SQL Server's Analysis Services uses OLE DB to connect to SQL Azure!
I develop a native/unmanaged application in Delphi that connects to SQL Server using ADO through the OLE DB provider for SQL Server. I'm considering adding SQL Azure support. It would be really helpful if I could reuse the majority of my code without not too much change. I probably wouldn't consider going this direction otherwise.
It would be helpful if Microsoft were more clear on why "OLE DB is not supported". If there are certain limitations within the use of OLE DB, what are they? Maybe I can work around them, or maybe it wouldn't affect me.
Microsoft also mentions that ODBC is supported. So could I use the "OLE DB provider to ODBC" and connect this way? Or is any combination that includes OLE DB "not supported"?
You can use it, however it has not been thoroughly tested for all cases. Essentially, it should work for most things, but there might be a few edge cases where it won't work. Until we document those cases, it remains unsupported. That being said, if you were to use and run into errors, we would love to know about it and prioritize that to be fixed.
Vote for the OleDB support for Azure here:
http://www.mygreatwindowsazureidea.com/forums/34685-sql-azure-feature-voting/suggestions/407269-ole-db-provider-for-connecting-to-sql-azure?ref=title
You can use ADO using the SQL Native Client although this information is hard to find you can read about it here http://msdn.microsoft.com/en-us/library/ms130978(SQL.110).aspx and here http://msdn.microsoft.com/en-us/library/ms131035(SQL.110).aspx.
In the connection string instead of using Provider=SQLOLEDB; we can use Provider=SQLNCLI10;. Also it is recommended to use DataTypeCompatibility=80;. So a SQL Native Client supported connection string would look like this:
"Provider=SQLNCLI10;Server=tcp:MyServerName.database.windows.net;Database=AdventureWorks2008R2;Uid=MyUserName#MyServerName;Pwd=MyPa$$w0rd;Encrypt=Yes;DataTypeCompatibility=80;"
You can also add "MARS Connection=True;" to the connection string for multiple recordsets.
I am developing a 3 tier database application.
1.) MS SQL DB
2.) Middle tier SOAP Server (with Delphi 7) connected to the DB
3.) Clients (first win32 gui (with Delphi 7) - later other platfomrs) connected to the SOAP server
I chose a SOAP Server to be open to various clients at a later stage (also some of the win32 gui clients will be stationed abroad - so the clients need to be thin) (this as suggested by Dr. Bob).
I am new to SOAP and have been looking at different examples and papers about authentication. But cant quite get my head around it.
I have made a SOAP server and client with Delphi's SOAP Server Application Wizard and added a SOAP SERVER Data Module, added a database connection and some datasets and providers. Connected the client with dbgrid etc and that part works fine.
But I want the client first to login and then be able to access data and I want the server to log each connection and also when the client logs off or is disconnected, so I am guessing I need the sessionID and a timeout. I also want the server to be able to tell the clients who else is "connected" (or whos session is still active) at any given time.
I have gathered that I need to make a authentication header, but cant figure out where or who I can get a sessionID. I presume that each time a client connectes to the server the server generates a sessionID? How do I get this?
Any help or suggestions/pointer would be appreciated,
thanks
Justin
Soap servers do not provide sessions by default. Your server has to implement Session life cycle managment (Login / Logout) etc.
A basic solution is documented here: Managing sessions with Delphi 6 Web services
Note however that this solution is far from perfect (see comments), for example it does not provide a session timeout mechanism.
OK - figured it out - I had not:
InvRegistry.RegisterHeaderClass(TypeInfo(IThorPayServerDB), TAuthHeader);
in the initialization
But I still cant figure out how to get the session ID - or some unique way of know which client session is loged in to the server - any ideas?
Delphi XE uses a newer version of SOAP, maybe that is the answer:
https://forums.embarcadero.com/thread.jspa?messageID=200793