resynching with databases

[Gary Shane Lim]

We have an access database. On the pc side of the program we write several
of the tables to an xml and then import them to the pda as a temporary
database. Then the tables are edited and added to. Then we port to an xml
file and back into the database they go. Here is my question. Several of the
tables are linked by an autonumber key. And we will have multiple pda
checking out data at a time. So if user a checks out with record 1-5 in
table 1 and adds 6-8 then user B also adds 6-8 when user B checks in It will
probably actually add 9-11. How do I get table 2 which has 2 records for
each record in table to relink to records 9-11 not 6-8. Does any of this
make sense? If anybody has any suggestions or I need to rewrite this so it
makes sense I will. Thanks again.

gslim

 

[Ginny Caughey [MVP]]

Gary,

This may be overkill, but I ended up using GUIDs for a scenario I had where
multiple CE devices were adding records that needed to be unique. I got the GUID
code here: http://smartdevices.microsoftdev.com/Learn/Articles/507.aspx The only
real downsize to GUIDs is that they are fairly bulky.

 

[Hollywood]

There was an article somewhere on the .NET concerning creating unique keys
for this situation, can't seem to find it again... would like to find it
myself. If anyone knows what article I'm speaking of, let us know!

 

[Ginny Caughey [MVP]]

Hollywood,

This is the only article I remember seeing:
http://smartdevices.microsoftdev.com/Learn/Articles/507.aspx
The GUIDs generated with this code are compatible with GUIDs generated on the
desktop.

 

[Chris Tacke, eMVP]

Another "more proper" way to do this is with a primary-key checkout
mechanism. Basically each client checks out a range or set of keys which it
can use for inserts, which guarantees uniqueness, doesn't require GUIDs, and
doesn't require key translation for lookups during syncing.

 

[Hollywood]

Thanks Ginny,

Could have sworn there was another article about doing something of the
sort, because I had initially thought of using GUIDs myself and then I could
have sworn I ran across this article.

 

[Gary Shane Lim]

Thanks guys that gives me some ideas


gslim

Another "more proper" way to do this is with a primary-key checkout
mechanism. Basically each client checks out a range or set of keys which it
can use for inserts, which guarantees uniqueness, doesn't require GUIDs, and
doesn't require key translation for lookups during syncing.

--
Chris Tacke, eMVP
Advisory Board Member
www.OpenNETCF.org
---
Windows CE Product Manager
Applied Data Systems
www.applieddata.net

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