A library built on top of the SQLAlchemy ORM for versioning row changes to relational SQL tables.
Authors: Ryan Kirkman and Akshay Nanavati
Build Status
Useful Links
Blog Post with more in depth design decisions
Getting Started
$ pip install versionalchemySample Usage
import sqlalchemy as sa
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.schema import UniqueConstraint
import versionalchemy as va
from versionalchemy.models import VAModelMixin, VALogMixin
MY_SQL_URL = '<insert mysql url here>'
engine = create_engine(MY_SQL_URL)
Base = declarative_base(bind=engine)
class Example(Base, VAModelMixin):
__tablename__ = 'example'
va_version_columns = ['id']
id = sa.Column(sa.Integer, primary_key=True)
value = sa.Column(sa.String(128))
class ExampleArchive(Base, VALogMixin):
__tablename__ = 'example_archive'
__table_args__ = (
UniqueConstraint('id', 'va_version'),
)
id = sa.Column(sa.Integer)
user_id = sa.Column(sa.Integer)
va.init() # Only call this once
Example.register(ExampleArchive, engine) # Call this once per engine, AFTER va.initLatency
We used benchmark.py to benchmark the performance of versionalchemy. It times the performance of the SQLAlchemy core, ORM without VersionAclehmy and ORM with VersionAlchemy for n inserts (where n was variable). Some results are below.
n |
Core Time |
ORM Time |
VA Time |
|---|---|---|---|
10000 |
9.81 s |
16.04 s |
36.13 |
100000 |
98.78 s |
158.87 s |
350.84 s |
VersionAlchemy performs roughly 2 times as bad as the ORM, which makes sense as we are doing roughly one additional insert per orm insert into the archive table.
Contributing
Make sure you have pip and virtualenv on your dev machine
Fork the repository and make the desired changes
Run make install to install all required dependencies
Run make lint tests to ensure the code is pep8 compliant and all tests pass. Note that the tests require 100% branch coverage to be considered passing
Open a pull request with a detailed explaination of the bug or feature
Respond to any comments. The PR will be merged if the travis CI build passes and the code changes are deemed sufficient by the admin
Style
Follow PEP8 with a line length of 100 characters
Prefer parenthesis to \ for line breaks
License
3 maintainers
Release files for versionalchemy 1.0.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| versionalchemy-1.0.0.tar.gz | 14.0 kB | Details |
Release files / versionalchemy-1.0.0.tar.gz
| Download URL | versionalchemy-1.0.0.tar.gz |
|---|---|
| Size | 14.0 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
78d64cf5587eb9a55c8ec1b7efd0e1a9e8ca5aca6ff2f1301a5d8c142522096d
|
|
BLAKE2b-256 checksum How to use checksums |
5b5c47abbfcfc485f35878c649ab7d6767a5fdd852e96eb6b0965f3ef857e655
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
No |
| Uploaded via |
twine/2.0.0 pkginfo/1.5.0.1 requests/2.22.0 setuptools/41.2.0 requests-toolbelt/0.9.1 tqdm/4.36.1 CPython/3.7.1
|
