Perform a "physical" (non-ManyToMany) field update.
(
self,
model,
old_field,
new_field,
old_type,
new_type,
old_db_params,
new_db_params,
strict=False,
)
| 358 | self._remake_table(model, delete_field=field) |
| 359 | |
| 360 | def _alter_field( |
| 361 | self, |
| 362 | model, |
| 363 | old_field, |
| 364 | new_field, |
| 365 | old_type, |
| 366 | new_type, |
| 367 | old_db_params, |
| 368 | new_db_params, |
| 369 | strict=False, |
| 370 | ): |
| 371 | """Perform a "physical" (non-ManyToMany) field update.""" |
| 372 | # Use "ALTER TABLE ... RENAME COLUMN" if only the column name |
| 373 | # changed and there aren't any constraints. |
| 374 | if ( |
| 375 | old_field.column != new_field.column |
| 376 | and self.column_sql(model, old_field) == self.column_sql(model, new_field) |
| 377 | and not ( |
| 378 | old_field.remote_field |
| 379 | and old_field.db_constraint |
| 380 | or new_field.remote_field |
| 381 | and new_field.db_constraint |
| 382 | ) |
| 383 | ): |
| 384 | return self.execute( |
| 385 | self._rename_field_sql( |
| 386 | model._meta.db_table, old_field, new_field, new_type |
| 387 | ) |
| 388 | ) |
| 389 | # Alter by remaking table |
| 390 | self._remake_table(model, alter_fields=[(old_field, new_field)]) |
| 391 | # Rebuild tables with FKs pointing to this field. |
| 392 | old_collation = old_db_params.get("collation") |
| 393 | new_collation = new_db_params.get("collation") |
| 394 | if new_field.unique and ( |
| 395 | old_type != new_type or old_collation != new_collation |
| 396 | ): |
| 397 | related_models = { |
| 398 | rel.related_model |
| 399 | for _, rel in _related_non_m2m_objects(old_field, new_field) |
| 400 | # Ignore self-relationship since the table was already rebuilt. |
| 401 | if rel.related_model != model |
| 402 | } |
| 403 | opts = new_field.model._meta |
| 404 | if new_field.primary_key: |
| 405 | for many_to_many in opts.many_to_many: |
| 406 | # Ignore self-relationship since the table was already |
| 407 | # rebuilt. |
| 408 | if many_to_many.related_model == model: |
| 409 | continue |
| 410 | if many_to_many.remote_field.through._meta.auto_created: |
| 411 | related_models.add(many_to_many.remote_field.through) |
| 412 | for related_model in related_models: |
| 413 | self._remake_table(related_model) |
| 414 | |
| 415 | def _alter_many_to_many(self, model, old_field, new_field, strict): |
| 416 | """Alter M2Ms to repoint their to= endpoints.""" |
nothing calls this directly
no test coverage detected