def _create_index_name(self, model, column_names, suffix=""):
"""
Generates a unique name for an index/unique constraint.
"""
# If there is just one column in the index, use a default algorithm from Django
if len(column_names) == 1 and not suffix:
return truncate_name(
'%s_%s' %
(model._meta.db_table, self._digest(column_names[0])),
self.connection.ops.max_name_length())
# Else generate the name for the index using a different algorithm
table_name = model._meta.db_table.replace('"', '').replace('.', '_')
index_unique_name = '_%s' % self._digest(table_name, *column_names)
max_length = self.connection.ops.max_name_length() or 200
# If the index name is too long, truncate it
index_name = ('%s_%s%s%s' % (
table_name,
column_names[0],
index_unique_name,
suffix,
)).replace('"', '').replace('.', '_')
if len(index_name) > max_length:
part = ('_%s%s%s' % (column_names[0], index_unique_name, suffix))
index_name = '%s%s' % (table_name[:(max_length - len(part))], part)
# It shouldn't start with an underscore (Oracle hates this)
if index_name[0] == "_":
index_name = index_name[1:]
# If it's STILL too long, just hash it down
if len(index_name) > max_length:
index_name = hashlib.md5(
force_bytes(index_name)).hexdigest()[:max_length]
# It can't start with a number on Oracle, so prepend D if we need to
if index_name[0].isdigit():
index_name = "D%s" % index_name[:-1]
return index_name
def contribute_to_class(self, cls, name):
from arouse._dj.db import connection
from arouse._dj.db.backends.utils import truncate_name
cls._meta = self
self.model = cls
# First, construct the default values for these options.
self.object_name = cls.__name__
self.model_name = self.object_name.lower()
self.verbose_name = camel_case_to_spaces(self.object_name)
# Store the original user-defined values for each option,
# for use when serializing the model definition
self.original_attrs = {}
# Next, apply any overridden values from 'class Meta'.
if self.meta:
meta_attrs = self.meta.__dict__.copy()
for name in self.meta.__dict__:
# Ignore any private attributes that Django doesn't care about.
# NOTE: We can't modify a dictionary's contents while looping
# over it, so we loop over the *original* dictionary instead.
if name.startswith('_'):
del meta_attrs[name]
for attr_name in DEFAULT_NAMES:
if attr_name in meta_attrs:
setattr(self, attr_name, meta_attrs.pop(attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
elif hasattr(self.meta, attr_name):
setattr(self, attr_name, getattr(self.meta, attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
self.unique_together = normalize_together(self.unique_together)
self.index_together = normalize_together(self.index_together)
# verbose_name_plural is a special case because it uses a 's'
# by default.
if self.verbose_name_plural is None:
self.verbose_name_plural = string_concat(
self.verbose_name, 's')
# order_with_respect_and ordering are mutually exclusive.
self._ordering_clash = bool(self.ordering
and self.order_with_respect_to)
# Any leftover attributes must be invalid.
if meta_attrs != {}:
raise TypeError("'class Meta' got invalid attribute(s): %s" %
','.join(meta_attrs.keys()))
else:
self.verbose_name_plural = string_concat(self.verbose_name, 's')
del self.meta
# If the db_table wasn't provided, use the app_label + model_name.
if not self.db_table:
self.db_table = "%s_%s" % (self.app_label, self.model_name)
self.db_table = truncate_name(self.db_table,
connection.ops.max_name_length())
def quote_name(self, name):
# SQL92 requires delimited (quoted) names to be case-sensitive. When
# not quoted, Oracle has case-insensitive behavior for identifiers, but
# always defaults to uppercase.
# We simplify things by making Oracle identifiers always uppercase.
if not name.startswith('"') and not name.endswith('"'):
name = '"%s"' % truncate_name(name.upper(), self.max_name_length())
# Oracle puts the query text into a (query % args) construct, so % signs
# in names need to be escaped. The '%%' will be collapsed back to '%' at
# that stage so we aren't really making the name longer here.
name = name.replace('%', '%%')
return name.upper()
def _get_trigger_name(self, table):
name_length = self.max_name_length() - 3
return '%s_TR' % truncate_name(table, name_length).upper()
def _get_sequence_name(self, table):
name_length = self.max_name_length() - 3
return '%s_SQ' % truncate_name(table, name_length).upper()