diff --git a/django/db/backends/oracle/schema.py b/django/db/backends/oracle/schema.py index e4b02fcc7b..a10bb08e17 100644 --- a/django/db/backends/oracle/schema.py +++ b/django/db/backends/oracle/schema.py @@ -1,6 +1,7 @@ import binascii import copy import datetime +import re from django.db.backends.base.schema import BaseDatabaseSchemaEditor from django.db.utils import DatabaseError @@ -49,44 +50,58 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): def alter_field(self, model, old_field, new_field, strict=False): try: - # Run superclass action super(DatabaseSchemaEditor, self).alter_field(model, old_field, new_field, strict) except DatabaseError as e: description = str(e) - # If we're changing to/from LOB fields, we need to do a + # If we're changing type to an unsupported type we need a # SQLite-ish workaround if 'ORA-22858' in description or 'ORA-22859' in description: - self._alter_field_lob_workaround(model, old_field, new_field) + self._alter_field_type_workaround(model, old_field, new_field) else: raise - def _alter_field_lob_workaround(self, model, old_field, new_field): + def _alter_field_type_workaround(self, model, old_field, new_field): """ - Oracle refuses to change a column type from/to LOB to/from a regular - column. In Django, this shows up when the field is changed from/to - a TextField. + Oracle refuses to change from some type to other type. What we need to do instead is: - - Add the desired field with a temporary name + - Add a nullable version of the desired field with a temporary name - Update the table to transfer values from old to new - Drop old column - - Rename the new column + - Rename the new column and possibly drop the nullable property """ # Make a new field that's like the new one but with a temporary # column name. new_temp_field = copy.deepcopy(new_field) + new_temp_field.null = True new_temp_field.column = self._generate_temp_name(new_field.column) # Add it self.add_field(model, new_temp_field) + # Explicit data type conversion + # https://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements002.htm#sthref340 + new_value = self.quote_name(old_field.column) + old_type = old_field.db_type(self.connection) + if re.match('^N?CLOB', old_type): + new_value = "TO_CHAR(%s)" % new_value + old_type = 'VARCHAR2' + if re.match('^N?VARCHAR2', old_type): + new_internal_type = new_field.get_internal_type() + if new_internal_type == 'DateField': + new_value = "TO_DATE(%s, 'YYYY-MM-DD')" % new_value + elif new_internal_type == 'DateTimeField': + new_value = "TO_TIMESTAMP(%s, 'YYYY-MM-DD HH24:MI:SS.FF')" % new_value + elif new_internal_type == 'TimeField': + # TimeField are stored as TIMESTAMP with a 1900-01-01 date part. + new_value = "TO_TIMESTAMP(CONCAT('1900-01-01 ', %s), 'YYYY-MM-DD HH24:MI:SS.FF')" % new_value # Transfer values across self.execute("UPDATE %s set %s=%s" % ( self.quote_name(model._meta.db_table), self.quote_name(new_temp_field.column), - self.quote_name(old_field.column), + new_value, )) # Drop the old field self.remove_field(model, old_field) - # Rename the new field - self.alter_field(model, new_temp_field, new_field) + # Rename and possibly make the new field NOT NULL + super(DatabaseSchemaEditor, self).alter_field(model, new_temp_field, new_field) def normalize_name(self, name): """ diff --git a/tests/schema/tests.py b/tests/schema/tests.py index 66a64ef31b..114d2bebaa 100644 --- a/tests/schema/tests.py +++ b/tests/schema/tests.py @@ -9,8 +9,8 @@ from django.db import ( from django.db.models import Model from django.db.models.fields import ( AutoField, BigIntegerField, BinaryField, BooleanField, CharField, - DateTimeField, IntegerField, PositiveIntegerField, SlugField, TextField, - TimeField, + DateField, DateTimeField, IntegerField, PositiveIntegerField, SlugField, + TextField, TimeField, ) from django.db.models.fields.related import ( ForeignKey, ManyToManyField, OneToOneField, @@ -448,18 +448,53 @@ class SchemaTests(TransactionTestCase): with connection.schema_editor() as editor: editor.alter_field(Note, old_field, new_field, strict=True) + def test_alter_text_field_to_date_field(self): + """ + #25002 - Test conversion of text field to date field. + """ + with connection.schema_editor() as editor: + editor.create_model(Note) + Note.objects.create(info='1988-05-05') + old_field = Note._meta.get_field('info') + new_field = DateField(blank=True) + new_field.set_attributes_from_name('info') + with connection.schema_editor() as editor: + editor.alter_field(Note, old_field, new_field, strict=True) + # Make sure the field isn't nullable + columns = self.column_classes(Note) + self.assertFalse(columns['info'][1][6]) + + def test_alter_text_field_to_datetime_field(self): + """ + #25002 - Test conversion of text field to datetime field. + """ + with connection.schema_editor() as editor: + editor.create_model(Note) + Note.objects.create(info='1988-05-05 3:16:17.4567') + old_field = Note._meta.get_field('info') + new_field = DateTimeField(blank=True) + new_field.set_attributes_from_name('info') + with connection.schema_editor() as editor: + editor.alter_field(Note, old_field, new_field, strict=True) + # Make sure the field isn't nullable + columns = self.column_classes(Note) + self.assertFalse(columns['info'][1][6]) + def test_alter_text_field_to_time_field(self): """ #25002 - Test conversion of text field to time field. """ with connection.schema_editor() as editor: editor.create_model(Note) - Note.objects.create(info='3:16') + Note.objects.create(info='3:16:17.4567') old_field = Note._meta.get_field('info') new_field = TimeField(blank=True) new_field.set_attributes_from_name('info') with connection.schema_editor() as editor: editor.alter_field(Note, old_field, new_field, strict=True) + # Make sure the field isn't nullable + columns = self.column_classes(Note) + self.assertFalse(columns['info'][1][6]) @skipIfDBFeature('interprets_empty_strings_as_nulls') def test_alter_textual_field_keep_null_status(self):