diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/releases/1.9.txt | 8 | ||||
| -rw-r--r-- | docs/topics/migrations.txt | 35 |
2 files changed, 37 insertions, 6 deletions
diff --git a/docs/releases/1.9.txt b/docs/releases/1.9.txt index 4e8fad3bf8..d87e0a6618 100644 --- a/docs/releases/1.9.txt +++ b/docs/releases/1.9.txt @@ -368,6 +368,14 @@ Management Commands to the database using the password from your settings file (instead of requiring it to be manually entered). +Migrations +^^^^^^^^^^ + +* Initial migrations are now marked with an :attr:`initial = True + <django.db.migrations.Migration.initial>` class attribute which allows + :djadminopt:`migrate --fake-initial <--fake-initial>` to more easily detect + initial migrations. + Models ^^^^^^ diff --git a/docs/topics/migrations.txt b/docs/topics/migrations.txt index 75373537c4..82354f96a8 100644 --- a/docs/topics/migrations.txt +++ b/docs/topics/migrations.txt @@ -276,6 +276,33 @@ class to make it importable:: Please refer to the notes about :ref:`historical-models` in migrations to see the implications that come along. +Initial migrations +~~~~~~~~~~~~~~~~~~ + +.. attribute:: Migration.initial + +.. versionadded:: 1.9 + +The "initial migrations" for an app are the migrations that create the first +version of that app's tables. Usually an app will have just one initial +migration, but in some cases of complex model interdependencies it may have two +or more. + +Initial migrations are marked with an ``initial = True`` class attribute on the +migration class. If an ``initial`` class attribute isn't found, a migration +will be considered "initial" if it is the first migration in the app (i.e. if +it has no dependencies on any other migration in the same app). + +When :djadmin:`migrate` is run with the :djadminopt:`--fake-initial` option, +these initial migrations are treated specially. For an initial migration that +creates one or more tables (``CreateModel`` operation), Django checks that all +of those tables already exist in the database and fake-applies the migration +if so. Similarly, for an initial migration that adds one or more fields +(``AddField`` operation), Django checks that all of the respective columns +already exist in the database and fake-applies the migration if so. Without +:djadminopt:`--fake-initial`, initial migrations are treated no differently +from any other migration. + Adding migrations to apps ------------------------- @@ -425,6 +452,7 @@ Then, open up the file; it should look something like this:: from django.db import models, migrations class Migration(migrations.Migration): + initial = True dependencies = [ ('yourappname', '0001_initial'), @@ -460,6 +488,7 @@ need to do is use the historical model and iterate over the rows:: person.save() class Migration(migrations.Migration): + initial = True dependencies = [ ('yourappname', '0001_initial'), @@ -761,12 +790,6 @@ If you already have pre-existing migrations created with without running them. (Django won't check that the table schema match your models, just that the right table names exist). -That's it! The only complication is if you have a circular dependency loop -of foreign keys; in this case, ``makemigrations`` might make more than one -initial migration, and you'll need to mark them all as applied using:: - - python manage.py migrate --fake yourappnamehere - .. versionchanged:: 1.8 The :djadminopt:`--fake-initial` flag was added to :djadmin:`migrate`; |