>> hi
>> 1st one: i am saving some object; the mapperExtension of the object
>> fires additional atomic updates of other things elsewhere
>> (aggregator).
>> These things has to be expired/refreshed... if i only knew them.
>> For certain cases, the object knows exactly which are these target
>> things. How (when) is best to expire these instances, i.e. assure that
>> nexttime they are used they will be re-fetched?
>> a) in the mapperext - this would be before the flush?
>> b) later, after flush, marking them somehow ?
>>
>
> the "public" way to mark an instance as expired is
> session.expire(instance). if you wanted to do this inside the mapper
> extension, i think its OK as long as you do the expire *after* the
> object has been inserted/updated (i.e. in after_insert() or
> after_update()).
>
ok i'll go this way then.
> We also have the capability to mark any group of attributes as
> expired. however I havent gotten around to building a nice public API
> for that, though i can show you the non-public way if you want to play
> with it. This API is used by the mapper after it saves your instance
> to mark attribues which require a post-fetch.
>
> What I'd like to do, and this has been frustrating me a bit, is to
> bring the "expire the whole instance", "expire a group of attributes",
> "reload a group of attributes", and "reload an instance" under one
> implementation umbrella - right now theres some repetition in there
> among Mapper, Query._get() and DeferredColumnLoader. I've sort of
> wanted to address the whole thing at once.
>
hmm, these seems to me like one
def reload( instance, later=False, attribs= ()): ...
with later=True meaning expire(), and non-empty attribs meaning "only
these".
but then this is generalizing the API not the implementation...
>> and, why atomic updates also have with commit after them? or is this
>> sqlite-specific?
>>
> every CRUD operation requires a commit. DBAPI is always inside of a
> transaction.
>
mmm i mean i have bunch of inserts and updates without a commit, and
then several atomic updates come with their own commits. and then one
more commit at the end.
e.g.
* SA: INFO BEGIN
* SA: INFO UPDATE "SequenceCounter" SET "curNum"=? WHERE
"SequenceCounter".db_id = ?
* SA: INFO [2, 8]
* SA: INFO INSERT INTO "Nalichnost" (kolvo_kym, cena, obj_id,
data_godnost, sklad_id, disabled, time_valid, kolvo_ot, stoka_id,
time_trans) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
* SA: INFO ['0', '978', None, None, 3, 0, None, '0', 1, None]
* SA: INFO INSERT INTO "Nalichnost" (kolvo_kym, cena, obj_id,
data_godnost, sklad_id, disabled, time_valid, kolvo_ot, stoka_id,
time_trans) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
* SA: INFO ['0', '94', None, None, 3, 0, None, '0', 1, None]
...
* SA: INFO INSERT INTO "DocItem" (kolichestvo, data_godnost, sk_ot_id,
number, sk_kym_id, opisanie, cena, stoka_id, doc_id) VALUES (?, ?, ?, ?,
?, ?, ?, ?, ?)
* SA: INFO ['702', None, None, 3, 5, None, '668', 1, 2]
* SA: INFO INSERT INTO "DocItem" (kolichestvo, data_godnost, sk_ot_id,
number, sk_kym_id, opisanie, cena, stoka_id, doc_id) VALUES (?, ?, ?, ?,
?, ?, ?, ?, ?)
* SA: INFO ['422', None, None, 4, 6, None, '17', 1, 2]
* SA: INFO UPDATE "Nalichnost" SET
kolvo_ot=(coalesce("Nalichnost".kolvo_ot, ?) + ?) WHERE
"Nalichnost".db_id = ?
* SA: INFO [0, 643, 4]
* SA: INFO COMMIT
* SA: INFO UPDATE "Nalichnost" SET
kolvo_kym=(coalesce("Nalichnost".kolvo_kym, ?) + ?) WHERE
"Nalichnost".db_id = ?
* SA: INFO [0, 643, None]
* SA: INFO COMMIT
* SA: INFO UPDATE "Nalichnost" SET
kolvo_ot=(coalesce("Nalichnost".kolvo_ot, ?) + ?) WHERE
"Nalichnost".db_id = ?
* SA: INFO [0, 702, 5]
* SA: INFO COMMIT
* SA: INFO UPDATE "Nalichnost" SET
kolvo_kym=(coalesce("Nalichnost".kolvo_kym, ?) + ?) WHERE
"Nalichnost".db_id = ?
* SA: INFO [0, 702, None]
* SA: INFO COMMIT
* SA: INFO UPDATE "Nalichnost" SET
kolvo_ot=(coalesce("Nalichnost".kolvo_ot, ?) + ?) WHERE
"Nalichnost".db_id = ?
* SA: INFO [0, 9, 3]
* SA: INFO COMMIT
* SA: INFO COMMIT
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