Quoting Mike B <[EMAIL PROTECTED]>:
--- Josh Sled <[EMAIL PROTECTED]> wrote:
Account data is primarily organized in the engine's
data objects, which
are located in src/engine/. The business module
is
nicely
compartmentalized into src/business/, and it's
"engine"-equivalent is in
src/business/business-core/.
What I'm confused about is how to load/store these
data objects. We can call this OR mapping or
serialization. I was under the impression that the
backend storage could change into an actual relational
layer.
Begin_edit/Commit_Edit is first, and then the qof_session_save() is the
second. The former are used in online storage systems (e.g. SQL), the
latter for
serialized storage (e.g. XML).
What database schema? What SQL queries? What OR
mapping layer?
GnuCash doesn't have these things, in the same way
other systems do.
Right, so as far as I can tell I need to interface
with the storage system by using the Query objects.
It seems like you can build queries of different
types, and that you build parameters and predicates
for them. I haven't seen any documentation about how
this really works, and I'm unclear about how to build
hese parameters and predicates (or even what is
possible to build). It's difficult to follow the code
through several layers of indirection in order to
discover these things, so I'm asking here. Again, an
example would really help me. A simple one would be
getting a list of business customers.
Look in src/business/business-gnome/dialog-customer.c -- at the end of
the file
is sets up the Search Dialog parameter lists for how to search for
customers. If you want a list of ALL customers you could build a query
that's effectively:
select * from customers where name matches-regex '.'
The parameters are just what you would think they are, starting with the
QueryFor object. So when you QueryFor Customer, all parameters are based on a
Customer. When you QueryFor Invoice, all parameters are based on an
invoice. So, for example, when searching for an invoice you can search
for:
<invoice>->Owner->Name matches "Company"
The parameter list for this predicate would be Owner, Name, <NULL>. Because
<invoice>->Owner->Name is a string, you need a String predicate to match
against this parameter.
It's all quite logical when you stop reading the code and think of the
architecture. There should even be some rudimentary docs in the source
tree on
this, and even in Doxygen.
Thanks,
- mike
-derek
--
Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
Member, MIT Student Information Processing Board (SIPB)
URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH
[EMAIL PROTECTED] PGP key available
_______________________________________________
gnucash-devel mailing list
[email protected]
https://lists.gnucash.org/mailman/listinfo/gnucash-devel
