Aarni Halinen
31 lines
973 B
Python
31 lines
973 B
Python
# contents of yourapp/migrations/custom_operations.py
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from django.db.migrations.operations.models import ModelOperation
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class AlterModelBases(ModelOperation):
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reduce_to_sql = False
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reversible = True
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def __init__(self, name, bases):
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self.bases = bases
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super().__init__(name)
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def state_forwards(self, app_label, state):
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"""
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Overwrite a models base classes with a custom list of
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bases instead, then force Django to reload the model
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with this (probably completely) different class hierarchy.
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"""
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state.models[app_label, self.name_lower].bases = self.bases
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state.reload_model(app_label, self.name_lower)
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def database_forwards(self, app_label, schema_editor, from_state, to_state):
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pass
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def database_backwards(self, app_label, schema_editor, from_state, to_state):
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pass
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def describe(self):
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return "Update %s bases to %s" % (self.name, self.bases)
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