mirror of
https://github.com/sqlalchemy/sqlalchemy.git
synced 2026-05-10 10:50:37 -04:00
Mike Bayer
5ab558004c
such that the Session, cache manager, declarative_base are part of environment, and custom cache code is portable and now within "caching_query.py". This allows the example to be easier to "drop in" to existing projects.
25 lines
916 B
Python
25 lines
916 B
Python
"""relationship_caching.py
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Load a set of Person and Address objects, specifying that
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related PostalCode, City, Country objects should be pulled from long
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term cache.
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"""
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from environment import Session, root
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from model import Person, Address, cache_address_bits
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from sqlalchemy.orm import joinedload
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import os
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for p in Session.query(Person).options(joinedload(Person.addresses), cache_address_bits):
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print p.format_full()
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print "\n\nIf this was the first run of relationship_caching.py, SQL was likely emitted to "\
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"load postal codes, cities, countries.\n"\
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"If run a second time, only a single SQL statement will run - all "\
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"related data is pulled from cache.\n"\
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"To clear the cache, delete the directory %r. \n"\
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"This will cause a re-load of cities, postal codes and countries on "\
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"the next run.\n"\
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% os.path.join(root, 'container_file')
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