I'm migrating several applications using
BDE that use CachedUpdates to
update several datasets within a single transaction. This is done to not
only to protect the updates within a dataset, but to insure several datasets
updates are made correctly (TDataSet CachedUpdates, rather than
TQuery/TStoredProc).
An example would be to get customers/orders/items/commissions/inventory/etc
all updated in a transaction. Master/detail and asynchronous detail all
commit or fail together.
I understand how to replace CachedUpdates very effectively with
TClientDataset. However, since we will be using
ADO (MS-
SQL Server 7) I was
wondering if I could find a replacement there. My thinking is that first
I'll migrate to
ADO; then, if our environment would benefit by 3-tier over
the current 2-tier approach, move it into
Midas.
Fedrov and Elmanova, Advanced Delphi Developer's Guide to
ADO, have one
brief comment in Appendix A "To use cached updates, it is possible to use
TADODataSet component with the LockType property equal to ltBachtOptimistic,
and use the UpdateBatch method to update multiple records in a single
operation."
Not yet deep enough into
ADO to understand how this could be used with
several datasets to form a transaction. Nor do I see any "Ah-ha, this is
it!" in that book or the D5 Developer's Guide.
Does anyone know of other literature, examples, code samples, whatever that
would help me get started in the right direction.
Thanks in Advance,
Quailin
BTW: Fedorov and Elmoanova looks to be an _excellent_ guide to using
ADO.
I've just got it and starting, but am confident it will be a reference as
well as tutor. Also, the D5 Demos\
ADO\ADOTest is an amazing compilation of
a whole bunch of
ADO ideas as well as a lot of interesting ideas for data
access and presentation.