Hi Craig...

>You shouldn't do it this way.

What do you mean, Should not pass the Diffgram? The diffgram will be in the biz tier.

>The data facade will then pass the data onto each "data adapter" layer. The DA will create the SQL CRUD commands that are specific to each database backend.

That's exactly what I'm trying to do.



>You shouldn't do it this way. The biz tier should connect to a data facade. The data facade will then pass the data onto each "data adapter" layer. The DA will create the SQL CRUD commands that are specific to each database backend. That way, the SQL statements can be optimized for each environment.

>Hi Craig.
>
>>You should have one data layer compenent for each data source
>
>I'm agree with you, I was talking about how to create my own parser to send to multiple backends (to use multiple behaviors also), finally I did it using the iXMLDOMElement propierty.
>
>In my data layer I was trying to get the elements of the Diffgram to create the proper SQL sentence (UPDATE, DELETE, INSERT), these Diffgram/Updategram will be send it by my Business Object:
>
>

>** DataAccess::UpdateData
>PARAMTERS lcDiffGram
>
>** oXA is my XMLAdapterObject
>
>This.oXA.LoadXML(lcDiffgram)
>oChild = This.oXA.iXMLDomElement.ChildNodes
>FOR EACH oNodes IN o oChild.Item(0).ChildNodes
>  ** Testing
>  ?oNodes.oNodeName
>  oElement = oNodes.GetElementByTagName(oNodes.FirstChild.NodeName)
>  FOR EACH oValues IN oElemenet.Item(0).ChildNodes
>     ?oValues.NodeName, oValues.Text
>    *** Here is where I will work with The Elements of the Diffgram
>    *** Now I can handle with different behaviors
>    *** Each oValues has the elements with changes
>    *** I can create the INSERT,UPDATE or DELETE statements
>  ENDFOR
>ENDFOR
>
>

>
>a Complete sample for testing:
>
>

>CLEAR
>CREATE CURSOR ctest (iid int AUTOINC , clave c(5), fecha d)
>SET MULTILOCKS ON
>FOR lnCounter=1 TO 5
>  INSERT INTO ctest (clave,fecha) VALUES (TRANSFORM(RAND()*1000,"@L 99999"),DATE()-(RAND()*50))
>endfor
>CURSORSETPROP("Buffering",5)
>CURSORSETPROP("keyfieldlist",'iID')
>* Lets change some values
>UPDATE cTest SET clave = '00001' WHERE iID = 1
>UPDATE cTest SET fecha = DATE(2005,11,02) WHERE iID = 3
>UPDATE cTest SET clave = '00099', fecha = DATE(2005,11,01) WHERE iID = 5
>** Create the XMLAdapter
>oXA = CREATEOBJECT("XMLAdapter")
>** Load the XMLupdategram
>oXA.LoadXML(XMLUPDATEGRAM("ctest"))
>oChild = oXA.IXMLDOMElement.childNodes
>FOR EACH oNodes IN oChild.item(0).childNodes
>  ?oNodes.NodeName
>  oEle = oNodes.GetElementsByTagName(oNodes.firstChild.nodeName)
>  FOR EACH oValues IN oEle.Item(0).ChildNodes
>    ?CHR(7),CHR(7),oValues.NodeName,"-->", oValues.Text
>  ENDFOR
>ENDFOR
>
>

>
>Any comments?
>
>>If you need to connect to multiple backends, the business objects should talk to a Data Facade object. It will then pass the data to a data layer component. You should have one data layer compenent for each data source (Visual FoxPro, SQL, Oracle, etc).
>
>
>>I've using XML to transport Visual FoxPro data between tiers in a COM+ DLL, it's pretty straigfull when you are using it to read the data.
>>
>>The new problem I've found is about how to send the update from the business tier to the data tier, with Visual FoxPro I can produce an XML Diffgram (trough XMLUpdategram() function or CursorAdapter class), but I'm finding problems to send this kind of XML when I prettend to not use MS SQLServer.
>>
>>It will be cool if I could create a .NET Adapter (SQLAdapter, OLEDBAdapter, etc) we could update any kind of datasource, obviously the mayor work will be in How to move between the Diffgram elements (the before/after elements).
>>
>>My question is: How can I move between Items in a XMLDiffgram?