So I am trying to do something interesting with my classes.
I am trying to implement history in the database.
To keep the ORM simple, they way I am approaching it is to have two
objects (Host vs HostRevision) and two tables (host vs host_revision)
that are connected by triggers.
Any changes made to 'host' (insert/update/delete), are copied (insert)
into the 'host_revision', with a version number. Then there is a Host
object and a HostRevision table. They have all the same columns,
except the later has a version number in it to distinguish the
different revisions.
So far the code looks like this:
class Host(Entity):
using_options(tablename="host")
name = Field(String(40))
hardware = Field(String(40))
class HostRevision(Entity):
using_options(tablename="host")
name = Field(String(40))
hardware = Field(String(40))
revision_number = Field(Integer)
The only difference between the two is that the second one has an
extra field.
Basically whenever I add a field to the first one, the second one
needs to have the field two.
Ideally I could look at the first one and build the second one. This
includes copying the columns, and foreign keys over in such a way as
to make them unique.
I assumed that I could look at the entity descriptor for the first and
build the second. Is this possible? Could I have some guidance at
when to do that and what data to pull from where?
n
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"SQLElixir" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sqlelixir?hl=en
-~----------~----~----~----~------~----~------~--~---
