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Albert Tugushev
30ee4263c0
<!-- Provide a general summary of your proposed changes in the Title field above --> ### Description <!-- Describe your changes in detail --> Remove print statements ### Checklist <!-- go over following points. check them with an `x` if they do apply, (they turn into clickable checkboxes once the PR is submitted, so no need to do everything at once) --> This pull request is: - [X] A documentation / typographical error fix - Good to go, no issue or tests are needed - [ ] A short code fix - please include the issue number, and create an issue if none exists, which must include a complete example of the issue. one line code fixes without an issue and demonstration will not be accepted. - Please include: `Fixes: #<issue number>` in the commit message - please include tests. one line code fixes without tests will not be accepted. - [ ] A new feature implementation - please include the issue number, and create an issue if none exists, which must include a complete example of how the feature would look. - Please include: `Fixes: #<issue number>` in the commit message - please include tests. **Have a nice day!** Closes: #5166 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5166 Pull-request-sha:04a7394f71Change-Id: Ib90a59fac929661a18748c6e44966fb87e3978c6 (cherry picked from commita836e3df5d)
35 lines
1.0 KiB
Python
35 lines
1.0 KiB
Python
"""
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Illustrates "vertical table" mappings.
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A "vertical table" refers to a technique where individual attributes
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of an object are stored as distinct rows in a table. The "vertical
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table" technique is used to persist objects which can have a varied
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set of attributes, at the expense of simple query control and brevity.
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It is commonly found in content/document management systems in order
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to represent user-created structures flexibly.
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Two variants on the approach are given. In the second, each row
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references a "datatype" which contains information about the type of
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information stored in the attribute, such as integer, string, or date.
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Example::
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shrew = Animal(u'shrew')
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shrew[u'cuteness'] = 5
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shrew[u'weasel-like'] = False
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shrew[u'poisonous'] = True
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session.add(shrew)
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session.flush()
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q = (session.query(Animal).
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filter(Animal.facts.any(
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and_(AnimalFact.key == u'weasel-like',
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AnimalFact.value == True))))
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print('weasel-like animals', q.all())
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.. autosource::
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"""
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