Kevin,
You work with .Net, right? Create a dataset with multiple related tables (or you can do that from within VFP using local tables), save as XML. Load that XML to XMLAdapter. It creates multiple tables. Each XMLtable has its own Diffgram and applydiffgram.
In other words do not use join when you can specify it with multiple hierarchical tables. If you use join then result is a single table and you need to manually update it then (and I don't know and easy way to that nor I support the idea updating multiple tables from a single view-similar).
Cetin


>Cetin,
>
>This example is exactly what I'm looking for. My only question is how to make this work
>with multiple tables, say as in a JOIN?
>
>If I have 2 or 3 tables JOINed together, and make changes to the resulting dataset,
>how do I then propogate the changes back to all base tables?
>
>Thanks
>
>Kevin
>
>
>
>
>>Yes and no. Depends on version. Under VFP9 you have the luxury doing this with XMLAdpater class. The diffgram I pasted is from VFP7. Here is a sample for VFP9 that both creates the diffgram (might be your COM1) and updates from XML diffgram (might be your COM2):
>>

>>LOCAL lcDiffXML
>>lcDiffXML = GetDiffGram() && COM1 creates diff.
>>UpdateFromDiffgram(m.lcDiffXML) && COM2 gets XML
>>
>>
>>PROCEDURE GetDiffGram
>>USE _samples+"\data\customer"
>>CURSORSETPROP("Buffering",5,'customer')
>>BROWSE TITLE "Modify on site 1"
>>
>>* Create diffgram xml
>>LOCAL lcChanges, oAdapter
>>oAdapter = CREATEOBJECT('xmlAdapter')
>>oAdapter.AddTableSchema('customer')
>>oAdapter.IsDiffgram = .T.
>>oAdapter.ToXML('lcChanges','',.f.,.t.,.t.)
>>* Closing data just for sampling
>>USE IN 'customer'
>>RETURN m.lcChanges
>>
>>PROCEDURE UpdateFromDiffgram(tcDiffGram)
>>LOCAL oAdapter
>>* just for sampling using a different alias
>>USE _samples+'data\customer' ALIAS myCustomer
>>* we don't want to save when we are sampling only
>>CURSORSETPROP("Buffering",5,'myCustomer')
>>BROWSE TITLE 'Before applying diffgram'
>>
>>oAdapter = CREATEOBJECT('xmlAdapter')
>>oAdapter.LoadXML(m.tcDiffGram,.f.)
>>oAdapter.Tables(1).Alias = 'myCustomer'
>>oAdapter.Tables(1).ApplyDiffgram()
>>BROWSE TITLE 'After applying diffgram'
>>

Too much hardcoding in there but this is a sample:)
>>PS: AFAIK you also work with .Net and you would like to know XMLAdapter is friendly with .Net datasets and diffgrams (also VFPOLEDB have as added support).
>>Cetin
>>
>>>Do I understand that I must store the changes back to the database myself? How is this
>>>done? There could be any number of records and field changed. Is there any way to do
>>>this automatically?
>>>
>>>
>>>
>>>>XmlUpdateGram() function creates an updategram (needs multilocks and buffering). That is it only includes updated/inserted/deleted records as updgram:before and after records. Suppose you updated customer table and changed company field, deleted ANATR and inserted NEWCUS. XmlUpdateGram('customer') produces an output like:
>>>>

>>>><?xml version = "1.0" encoding="Windows-1252" standalone="yes"?>
>>>><root xmlns:updg="urn:schemas-microsoft-com:xml-updategram">
>>>>	<updg:sync>
>>>>		<updg:before>
>>>>			<customer>
>>>>				<cust_id>ALFKI</cust_id>
>>>>				<company>Alfreds Futterkiste</company>
>>>>* other fields here
>>>>			</customer>
>>>>		</updg:before>
>>>>		<updg:after>
>>>>			<customer>
>>>>				<cust_id>ALFKI</cust_id>
>>>>				<company>Alfreds Futterkiste-Updated</company>
>>>>* other fields here
>>>>			</customer>
>>>>		</updg:after>
>>>>		<updg:before>
>>>>			<customer>
>>>>* all fields here - unmodified
>>>>			</customer>
>>>>		</updg:before>
>>>>		<updg:after/>
>>>>		<updg:before/>
>>>>		<updg:after>
>>>>			<customer>
>>>>				<cust_id>NEWCUS</cust_id>
>>>>* other fields here
>>>>			</customer>
>>>>		</updg:after>
>>>>	</updg:sync>
>>>></root>
>>>>

Instead of receiving the whole table diffgram approach only gets 'differences' IOW. On receving side you have to process this yourself however (ie: XMLDocument). VFP9 CA and XMLAdapter might help you to work with them in an easier way. Check www.prenia.com for samples.
>>>>Cetin
>>>>
>>>>
>>>>>The reason I'm using COM is because I will need to update the
>>>>>application piece by piece. I don't want everything compiled
>>>>>into one big EXE.
>>>>>
>>>>>Can you elaborate on the DiffGram option?
>>>>>
>>>>>
>>>>>
>>>>>>Hmm that in turn would bring up other questions. Ways to go are more than one and which one to choose depends. ie: One scenario:
>>>>>>
>>>>>>Instead of CursorToXml and XmlTocursor you might choose ADO and pass an ADO recordset instead.
>>>>>>Another one is to pass a diffgram instead of all rows using CursorToXML and XMLToCursor.
>>>>>>Yet another one might be passing just an array of records that are updated/added/deleted with flags.
>>>>>>
>>>>>>Actually first I would think of "do I really want to talk between COM objects or even do I want a single COM object in my application" - sounds like I don't like COM objects:) Really I don't, too much problems with them for me (call it DLL hell, security etc etc).
>>>>>>
>>>>>>If one of them can connect to data why would other one cannot and a need for 2 evils?
>>>>>>Cetin
>>>>>>
>>>>>>>Thanks. This brings up another question.
>>>>>>>
>>>>>>>I want to use CURSORTOXML() and XMLTOCURSOR() to pass data to and
>>>>>>>from COM objects.
>>>>>>>
>>>>>>>Once I make changes to data and convert it to XML, and after I use
>>>>>>>XMLTOCURSOR() to create a cursor, whats the best way to update the
>>>>>>>database?
>>>>>>>
>>>>>>>I am using a VFP database now, with possible plans later to convert
>>>>>>>to SQL Server.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>For the 'nOutputFormat', 'nFlags', 'cSchemaName', 'cSchemaLocation', and 'cNameSpace'
>>>>>>>>>parameters, are there any standards as far as what settings I should use?
>>>>>>>>>
>>>>>>>>>I am only using the command to pass data back & forth between COM objects.
>>>>>>>>
>>>>>>>>If there were standards there wouldn't be flags;)
>>>>>>>>nOutputFormat: 2 or 3 are my favorites. More compact.
>>>>>>>>nFlags: 1 to make it compact.
>>>>>>>>For others it depends. Probably "1" inline schema would be good.
>>>>>>>>
>>>>>>>>With these settings:
>>>>>>>>CursorToXml('myAlias','myMemvar',2,1,0,"1")
>>>>>>>>would create a compact XML with inline schema and store in m.myMemvar and IMHO is good for your need.
>>>>>>>>Cetin