You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Enso-Bot/venv/Lib/site-packages/south/db/oracle.py

346 lines
14 KiB
Python

from __future__ import print_function
import os.path
import sys
import re
import warnings
import cx_Oracle
from django.db import connection, models
from django.db.backends.util import truncate_name
from django.core.management.color import no_style
from django.db.models.fields import NOT_PROVIDED
from django.db.utils import DatabaseError
# In revision r16016 function get_sequence_name has been transformed into
# method of DatabaseOperations class. To make code backward-compatible we
# need to handle both situations.
try:
from django.db.backends.oracle.base import get_sequence_name\
as original_get_sequence_name
except ImportError:
original_get_sequence_name = None
from south.db import generic
class DatabaseOperations(generic.DatabaseOperations):
"""
Oracle implementation of database operations.
"""
backend_name = 'oracle'
alter_string_set_type = 'ALTER TABLE %(table_name)s MODIFY %(column)s %(type)s %(nullity)s;'
alter_string_set_default = 'ALTER TABLE %(table_name)s MODIFY %(column)s DEFAULT %(default)s;'
alter_string_update_nulls_to_default = \
'UPDATE %(table_name)s SET %(column)s = %(default)s WHERE %(column)s IS NULL;'
add_column_string = 'ALTER TABLE %s ADD %s;'
delete_column_string = 'ALTER TABLE %s DROP COLUMN %s;'
add_constraint_string = 'ALTER TABLE %(table_name)s ADD CONSTRAINT %(constraint)s %(clause)s'
allows_combined_alters = False
has_booleans = False
constraints_dict = {
'P': 'PRIMARY KEY',
'U': 'UNIQUE',
'C': 'CHECK',
'R': 'FOREIGN KEY'
}
def get_sequence_name(self, table_name):
if original_get_sequence_name is None:
return self._get_connection().ops._get_sequence_name(table_name)
else:
return original_get_sequence_name(table_name)
#TODO: This will cause very obscure bugs if anyone uses a column name or string value
# that looks like a column definition (with 'CHECK', 'DEFAULT' and/or 'NULL' in it)
# e.g. "CHECK MATE" varchar(10) DEFAULT 'NULL'
def adj_column_sql(self, col):
# Syntax fixes -- Oracle is picky about clause order
col = re.sub('(?P<constr>CHECK \(.*\))(?P<any>.*)(?P<default>DEFAULT \d+)',
lambda mo: '%s %s%s'%(mo.group('default'), mo.group('constr'), mo.group('any')), col) #syntax fix for boolean/integer field only
col = re.sub('(?P<not_null>(NOT )?NULL) (?P<misc>(.* )?)(?P<default>DEFAULT.+)',
lambda mo: '%s %s %s'%(mo.group('default'),mo.group('not_null'),mo.group('misc') or ''), col) #fix order of NULL/NOT NULL and DEFAULT
return col
def check_meta(self, table_name):
return table_name in [ m._meta.db_table for m in models.get_models() ] #caching provided by Django
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
@generic.invalidate_table_constraints
def create_table(self, table_name, fields):
qn = self.quote_name(table_name)
columns = []
autoinc_sql = ''
for field_name, field in fields:
field = self._field_sanity(field)
# avoid default values in CREATE TABLE statements (#925)
field._suppress_default = True
col = self.column_sql(table_name, field_name, field)
if not col:
continue
col = self.adj_column_sql(col)
columns.append(col)
if isinstance(field, models.AutoField):
autoinc_sql = connection.ops.autoinc_sql(table_name, field_name)
sql = 'CREATE TABLE %s (%s);' % (qn, ', '.join([col for col in columns]))
self.execute(sql)
if autoinc_sql:
self.execute(autoinc_sql[0])
self.execute(autoinc_sql[1])
@generic.invalidate_table_constraints
def delete_table(self, table_name, cascade=True):
qn = self.quote_name(table_name)
# Note: PURGE is not valid syntax for Oracle 9i (it was added in 10)
if cascade:
self.execute('DROP TABLE %s CASCADE CONSTRAINTS;' % qn)
else:
self.execute('DROP TABLE %s;' % qn)
# If the table has an AutoField a sequence was created.
sequence_sql = """
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.get_sequence_name(table_name)}
self.execute(sequence_sql)
@generic.invalidate_table_constraints
def alter_column(self, table_name, name, field, explicit_name=True, ignore_constraints=False):
if self.dry_run:
if self.debug:
print(' - no dry run output for alter_column() due to dynamic DDL, sorry')
return
qn = self.quote_name(table_name)
# hook for the field to do any resolution prior to it's attributes being queried
if hasattr(field, 'south_init'):
field.south_init()
field = self._field_sanity(field)
# Add _id or whatever if we need to
field.set_attributes_from_name(name)
if not explicit_name:
name = field.column
qn_col = self.quote_name(name)
# First, change the type
# This will actually also add any CHECK constraints needed,
# since e.g. 'type' for a BooleanField is 'NUMBER(1) CHECK (%(qn_column)s IN (0,1))'
params = {
'table_name':qn,
'column': qn_col,
'type': self._db_type_for_alter_column(field),
'nullity': 'NOT NULL',
'default': 'NULL'
}
if field.null:
params['nullity'] = 'NULL'
sql_templates = [
(self.alter_string_set_type, params, []),
(self.alter_string_set_default, params, []),
]
if not field.null and field.has_default():
# Use default for rows that had nulls. To support the case where
# the new default does not fit the old type, we need to first change
# the column type to the new type, but null=True; then set the default;
# then complete the type change.
def change_params(**kw):
"A little helper for non-destructively changing the params"
p = params.copy()
p.update(kw)
return p
sql_templates[:0] = [
(self.alter_string_set_type, change_params(nullity='NULL'),[]),
(self.alter_string_update_nulls_to_default, change_params(default="%s"), [field.get_default()]),
]
if not ignore_constraints:
# drop CHECK constraints. Make sure this is executed before the ALTER TABLE statements
# generated above, since those statements recreate the constraints we delete here.
check_constraints = self._constraints_affecting_columns(table_name, [name], "CHECK")
for constraint in check_constraints:
self.execute(self.delete_check_sql % {
'table': self.quote_name(table_name),
'constraint': self.quote_name(constraint),
})
# Drop foreign constraints
try:
self.delete_foreign_key(qn, qn_col)
except ValueError:
# There weren't any
pass
for sql_template, params, args in sql_templates:
try:
self.execute(sql_template % params, args, print_all_errors=False)
except DatabaseError as exc:
description = str(exc)
# Oracle complains if a column is already NULL/NOT NULL
if 'ORA-01442' in description or 'ORA-01451' in description:
# so we just drop NULL/NOT NULL part from target sql and retry
params['nullity'] = ''
sql = sql_template % params
self.execute(sql)
# Oracle also has issues if we try to change a regular column
# to a LOB or vice versa (also REF, object, VARRAY or nested
# table, but these don't come up much in Django apps)
elif 'ORA-22858' in description or 'ORA-22859' in description:
self._alter_column_lob_workaround(table_name, name, field)
else:
self._print_sql_error(exc, sql_template % params)
raise
if not ignore_constraints:
# Add back FK constraints if needed
if field.rel: #and self.supports_foreign_keys:
self.add_deferred_sql(
self.foreign_key_sql(
qn[1:-1], # foreign_key_sql uses this as part of constraint name
qn_col[1:-1], # foreign_key_sql uses this as part of constraint name
field.rel.to._meta.db_table,
field.rel.to._meta.get_field(field.rel.field_name).column
)
)
def _alter_column_lob_workaround(self, table_name, name, 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:
- Rename the original column
- Add the desired field as new
- Update the table to transfer values from old to new
- Drop old column
"""
renamed = self._generate_temp_name(name)
self.rename_column(table_name, name, renamed)
self.add_column(table_name, name, field, keep_default=False)
self.execute("UPDATE %s set %s=%s" % (
self.quote_name(table_name),
self.quote_name(name),
self.quote_name(renamed),
))
self.delete_column(table_name, renamed)
def _generate_temp_name(self, for_name):
suffix = hex(hash(for_name)).upper()[1:]
return self.normalize_name(for_name + "_" + suffix)
@generic.copy_column_constraints #TODO: Appears to be nulled by the delete decorator below...
@generic.delete_column_constraints
def rename_column(self, table_name, old, new):
if old == new:
# Short-circuit out
return []
self.execute('ALTER TABLE %s RENAME COLUMN %s TO %s;' % (
self.quote_name(table_name),
self.quote_name(old),
self.quote_name(new),
))
@generic.invalidate_table_constraints
def add_column(self, table_name, name, field, keep_default=False):
field = self._field_sanity(field)
sql = self.column_sql(table_name, name, field)
sql = self.adj_column_sql(sql)
if sql:
params = (
self.quote_name(table_name),
sql
)
sql = self.add_column_string % params
self.execute(sql)
# Now, drop the default if we need to
if field.default is not None:
field.default = NOT_PROVIDED
self.alter_column(table_name, name, field, explicit_name=False, ignore_constraints=True)
def delete_column(self, table_name, name):
return super(DatabaseOperations, self).delete_column(self.quote_name(table_name), name)
def lookup_constraint(self, db_name, table_name, column_name=None):
if column_name:
# Column names in the constraint cache come from the database,
# make sure we use the properly shortened/uppercased version
# for lookup.
column_name = self.normalize_name(column_name)
return super(DatabaseOperations, self).lookup_constraint(db_name, table_name, column_name)
def _constraints_affecting_columns(self, table_name, columns, type="UNIQUE"):
if columns:
columns = [self.normalize_name(c) for c in columns]
return super(DatabaseOperations, self)._constraints_affecting_columns(table_name, columns, type)
def _field_sanity(self, field):
"""
This particular override stops us sending DEFAULTs for BooleanField.
"""
if isinstance(field, models.BooleanField) and field.has_default():
field.default = int(field.to_python(field.get_default()))
# On Oracle, empty strings are null
if isinstance(field, (models.CharField, models.TextField)):
field.null = field.empty_strings_allowed
return field
def _default_value_workaround(self, value):
from datetime import date,time,datetime
if isinstance(value, (date,time,datetime)):
return "'%s'" % value
else:
return super(DatabaseOperations, self)._default_value_workaround(value)
def _fill_constraint_cache(self, db_name, table_name):
self._constraint_cache.setdefault(db_name, {})
self._constraint_cache[db_name][table_name] = {}
rows = self.execute("""
SELECT user_cons_columns.constraint_name,
user_cons_columns.column_name,
user_constraints.constraint_type
FROM user_constraints
JOIN user_cons_columns ON
user_constraints.table_name = user_cons_columns.table_name AND
user_constraints.constraint_name = user_cons_columns.constraint_name
WHERE user_constraints.table_name = '%s'
""" % self.normalize_name(table_name))
for constraint, column, kind in rows:
self._constraint_cache[db_name][table_name].setdefault(column, set())
self._constraint_cache[db_name][table_name][column].add((self.constraints_dict[kind], constraint))
return