Django Migrations: A Retrospective

Transcript

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   Andrew Godwin @andrewgodwin migrations: a retrospective

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   Andrew Godwin Author of South migrations library Hi, I'm Author

   of 1.7 Django migrations I like my tea iced, and my schemas explicit
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   Django/Python backend I work for Discovery? Mobile? Storage? UI? On-site?

   ...auditing? We have it all. We're hiring!
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   Migrations They're pretty good.

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   South ...it was good for its time

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   The Initial Plan Django Schema backend ORM Hooks South 2

   Migration handling User interface
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   The Revised Plan Django Schema backend ORM Hooks South 2

   Migration handling User interface Backport for 1.4 - 1.6
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   The Revised Revised Plan Django Schema backend ORM Hooks Migration

   handling User interface
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   Logically Separate SchemaEditor Schema Migrations field.deconstruct() ModelOptions.apps Operations Loader /

   Graph Executor Autodetector Optimiser State
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    makemigrations field.deconstruct() Loader / Graph Autodetector Optimiser State Writer 1

    2 State 3 5 4
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    migrate SchemaEditor ModelOptions.apps Operations Loader / Graph Executor State 1

    2 Recorder 3
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    Moving South into Django instead, "Adding migrations to Django"

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    A New Format More concise Declarative Introspectable

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    Migration actions Frozen ORM

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    None
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    In-memory running Creates models from migration sets Autodetector diffs created

    from on-disk Used to feed SchemaEditor / ORM
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    But what went wrong?

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    Swappable Models

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    Your migration dependencies myapp/0001 myapp/0002 otherapp/0001 auth/0001 contenttypes/0001

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    myapp/0001 myapp/0002 otherapp/0001 auth/0001 contenttypes/0001 thirdapp/0001 Your migration dependencies on

    swappable models
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    what? Your migration dependencies on swappable models myapp/0001 myapp/0002 otherapp/0001

    auth/0001 contenttypes/0001 thirdapp/0001 ???
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    what? Your migration dependencies on swappable models myapp/0001 myapp/0002 otherapp/0001

    auth/0001 contenttypes/0001 thirdapp/0001 ???
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    Unmigrated Apps

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    Test persistence

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    Test persistence on MySQL

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    Random Meta options order_with_respect_to? Really?

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    Proxy Models

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    But we're close! Django 1.7, coming to a server near

    you soon.
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    Thanks! Andrew Godwin andrewgodwin@eventbrite.com