Fix Oracle's default handling and schema-prepared-statement issue

This commit is contained in:
Andrew Godwin 2013-08-23 12:07:55 +01:00
parent ac45f9c9c5
commit 9cc6cfc405
4 changed files with 62 additions and 9 deletions

View File

@ -654,6 +654,12 @@ class BaseDatabaseFeatures(object):
# supported by the Python driver
supports_paramstyle_pyformat = True
# Does the backend require literal defaults, rather than parameterised ones?
requires_literal_defaults = False
# Does the backend require a connection reset after each material schema change?
connection_persists_old_columns = False
def __init__(self, connection):
self.connection = connection

View File

@ -94,6 +94,8 @@ class DatabaseFeatures(BaseDatabaseFeatures):
supports_combined_alters = False
max_index_name_length = 30
nulls_order_largest = True
requires_literal_defaults = True
connection_persists_old_columns = True
class DatabaseOperations(BaseDatabaseOperations):

View File

@ -1,4 +1,6 @@
import copy
import datetime
from django.utils import six
from django.db.backends.schema import BaseDatabaseSchemaEditor
from django.db.utils import DatabaseError
@ -89,3 +91,13 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
"""
suffix = hex(hash(for_name)).upper()[1:]
return self.normalize_name(for_name + "_" + suffix)
def prepare_default(self, value):
if isinstance(value, (datetime.date, datetime.time, datetime.datetime)):
return "'%s'" % value
elif isinstance(value, six.string_types):
return repr(value)
elif isinstance(value, bool):
return "1" if value else "0"
else:
return str(value)

View File

@ -116,6 +116,12 @@ class BaseDatabaseSchemaEditor(object):
# If we were told to include a default value, do so
default_value = self.effective_default(field)
if include_default and default_value is not None:
if self.connection.features.requires_literal_defaults:
# Some databases can't take defaults as a parameter (oracle)
# If this is the case, the individual schema backend should
# implement prepare_default
sql += " DEFAULT %s" % self.prepare_default(default_value)
else:
sql += " DEFAULT %s"
params += [default_value]
# Oracle treats the empty string ('') as null, so coerce the null
@ -135,6 +141,12 @@ class BaseDatabaseSchemaEditor(object):
# Return the sql
return sql, params
def prepare_default(self, value):
"""
Only used for backends which have requires_literal_defaults feature
"""
raise NotImplementedError()
def effective_default(self, field):
"""
Returns a field's effective database default value
@ -385,6 +397,9 @@ class BaseDatabaseSchemaEditor(object):
"to_column": self.quote_name(to_column),
}
)
# Reset connection if required
if self.connection.features.connection_persists_old_columns:
self.connection.close()
def remove_field(self, model, field):
"""
@ -405,6 +420,9 @@ class BaseDatabaseSchemaEditor(object):
"column": self.quote_name(field.column),
}
self.execute(sql)
# Reset connection if required
if self.connection.features.connection_persists_old_columns:
self.connection.close()
def alter_field(self, model, old_field, new_field, strict=False):
"""
@ -522,6 +540,18 @@ class BaseDatabaseSchemaEditor(object):
},
[],
))
else:
if self.connection.features.requires_literal_defaults:
# Some databases can't take defaults as a parameter (oracle)
# If this is the case, the individual schema backend should
# implement prepare_default
actions.append((
self.sql_alter_column_default % {
"column": self.quote_name(new_field.column),
"default": self.prepare_default(new_default),
},
[],
))
else:
actions.append((
self.sql_alter_column_default % {
@ -628,6 +658,9 @@ class BaseDatabaseSchemaEditor(object):
"check": new_db_params['check'],
}
)
# Reset connection if required
if self.connection.features.connection_persists_old_columns:
self.connection.close()
def _alter_many_to_many(self, model, old_field, new_field, strict):
"""