112 lines
4.4 KiB
Python
112 lines
4.4 KiB
Python
import copy
|
|
import datetime
|
|
import binascii
|
|
|
|
from django.utils import six
|
|
from django.utils.text import force_text
|
|
from django.db.backends.schema import BaseDatabaseSchemaEditor
|
|
from django.db.utils import DatabaseError
|
|
|
|
|
|
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
|
|
|
|
sql_create_column = "ALTER TABLE %(table)s ADD %(column)s %(definition)s"
|
|
sql_alter_column_type = "MODIFY %(column)s %(type)s"
|
|
sql_alter_column_null = "MODIFY %(column)s NULL"
|
|
sql_alter_column_not_null = "MODIFY %(column)s NOT NULL"
|
|
sql_alter_column_default = "MODIFY %(column)s DEFAULT %(default)s"
|
|
sql_alter_column_no_default = "MODIFY %(column)s DEFAULT NULL"
|
|
sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s"
|
|
sql_delete_table = "DROP TABLE %(table)s CASCADE CONSTRAINTS"
|
|
|
|
def quote_value(self, value):
|
|
if isinstance(value, (datetime.date, datetime.time, datetime.datetime)):
|
|
return "'%s'" % value
|
|
elif isinstance(value, six.string_types):
|
|
return "'%s'" % six.text_type(value).replace("\'", "\'\'")
|
|
elif isinstance(value, six.buffer_types):
|
|
return "'%s'" % force_text(binascii.hexlify(value))
|
|
elif isinstance(value, bool):
|
|
return "1" if value else "0"
|
|
else:
|
|
return str(value)
|
|
|
|
def delete_model(self, model):
|
|
# Run superclass action
|
|
super(DatabaseSchemaEditor, self).delete_model(model)
|
|
# Clean up any autoincrement trigger
|
|
self.execute("""
|
|
DECLARE
|
|
i INTEGER;
|
|
BEGIN
|
|
SELECT COUNT(*) INTO i FROM USER_CATALOG
|
|
WHERE TABLE_NAME = '%(sq_name)s' AND TABLE_TYPE = 'SEQUENCE';
|
|
IF i = 1 THEN
|
|
EXECUTE IMMEDIATE 'DROP SEQUENCE "%(sq_name)s"';
|
|
END IF;
|
|
END;
|
|
/""" % {'sq_name': self.connection.ops._get_sequence_name(model._meta.db_table)})
|
|
|
|
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
|
|
# SQLite-ish workaround
|
|
if 'ORA-22858' in description or 'ORA-22859' in description:
|
|
self._alter_field_lob_workaround(model, old_field, new_field)
|
|
else:
|
|
raise
|
|
|
|
def _alter_field_lob_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.
|
|
What we need to do instead is:
|
|
- Add the desired field with a temporary name
|
|
- Update the table to transfer values from old to new
|
|
- Drop old column
|
|
- Rename the new column
|
|
"""
|
|
# 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.column = self._generate_temp_name(new_field.column)
|
|
# Add it
|
|
self.add_field(model, new_temp_field)
|
|
# 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),
|
|
))
|
|
# Drop the old field
|
|
self.remove_field(model, old_field)
|
|
# Rename the new field
|
|
self.alter_field(model, new_temp_field, new_field)
|
|
# Close the connection to force cx_Oracle to get column types right
|
|
# on a new cursor
|
|
self.connection.close()
|
|
|
|
def normalize_name(self, name):
|
|
"""
|
|
Get the properly shortened and uppercased identifier as returned by quote_name(), but without the actual quotes.
|
|
"""
|
|
nn = self.quote_name(name)
|
|
if nn[0] == '"' and nn[-1] == '"':
|
|
nn = nn[1:-1]
|
|
return nn
|
|
|
|
def _generate_temp_name(self, for_name):
|
|
"""
|
|
Generates temporary names for workarounds that need temp columns
|
|
"""
|
|
suffix = hex(hash(for_name)).upper()[1:]
|
|
return self.normalize_name(for_name + "_" + suffix)
|
|
|
|
def prepare_default(self, value):
|
|
return self.quote_value(value)
|