python - how to control version of data object (instance) in sqlalchemy? -

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python - how to control version of data object (instance) in sqlalchemy? -

how 1 set model in sqlalchemy have versioncontrol in instance(column_version)?

unique pk on table.

unique version on pk.

archive-flag (latest version not archived).

e.g.

init= object: -------------- *version;update;user;id;archive;rest* 1;2012-01-01;usera; uniquekey;no;data=green on_update= object -------------- *version;update;user;id;archive;rest* 1;2012-01-01;usera; uniquekey;**yes**;data=green **2**;2012-01-05;userb; uniquekey;no;data=red

has thought on how accomplish that? or experience?

i thinking 2 db's right (archive, active) archive holds "old"versions (pk = uniquekey+ version) while active (pk = uniquekey).

(for inquire why should so?

im thinking difference between consistence &coherence mapping--> 1 either map specific version object1 version7 or actual version object1).

python sqlalchemy version

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