160 lines
5.4 KiB
Python
160 lines
5.4 KiB
Python
# orm/sync.py
|
|
# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors
|
|
# <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""private module containing functions used for copying data
|
|
between instances based on join conditions.
|
|
|
|
"""
|
|
|
|
from . import attributes
|
|
from . import exc
|
|
from . import util as orm_util
|
|
|
|
|
|
def populate(
|
|
source,
|
|
source_mapper,
|
|
dest,
|
|
dest_mapper,
|
|
synchronize_pairs,
|
|
uowcommit,
|
|
flag_cascaded_pks,
|
|
):
|
|
source_dict = source.dict
|
|
dest_dict = dest.dict
|
|
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
# inline of source_mapper._get_state_attr_by_column
|
|
prop = source_mapper._columntoproperty[l]
|
|
value = source.manager[prop.key].impl.get(
|
|
source, source_dict, attributes.PASSIVE_OFF
|
|
)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, dest_mapper, r)
|
|
|
|
try:
|
|
# inline of dest_mapper._set_state_attr_by_column
|
|
prop = dest_mapper._columntoproperty[r]
|
|
dest.manager[prop.key].impl.set(dest, dest_dict, value, None)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(True, source_mapper, l, dest_mapper, r)
|
|
|
|
# technically the "r.primary_key" check isn't
|
|
# needed here, but we check for this condition to limit
|
|
# how often this logic is invoked for memory/performance
|
|
# reasons, since we only need this info for a primary key
|
|
# destination.
|
|
if (
|
|
flag_cascaded_pks
|
|
and l.primary_key
|
|
and r.primary_key
|
|
and r.references(l)
|
|
):
|
|
uowcommit.attributes[("pk_cascaded", dest, r)] = True
|
|
|
|
|
|
def bulk_populate_inherit_keys(source_dict, source_mapper, synchronize_pairs):
|
|
# a simplified version of populate() used by bulk insert mode
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
prop = source_mapper._columntoproperty[l]
|
|
value = source_dict[prop.key]
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, source_mapper, r)
|
|
|
|
try:
|
|
prop = source_mapper._columntoproperty[r]
|
|
source_dict[prop.key] = value
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(True, source_mapper, l, source_mapper, r)
|
|
|
|
|
|
def clear(dest, dest_mapper, synchronize_pairs):
|
|
for l, r in synchronize_pairs:
|
|
if (
|
|
r.primary_key
|
|
and dest_mapper._get_state_attr_by_column(dest, dest.dict, r)
|
|
not in orm_util._none_set
|
|
):
|
|
|
|
raise AssertionError(
|
|
"Dependency rule tried to blank-out primary key "
|
|
"column '%s' on instance '%s'" % (r, orm_util.state_str(dest))
|
|
)
|
|
try:
|
|
dest_mapper._set_state_attr_by_column(dest, dest.dict, r, None)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(True, None, l, dest_mapper, r)
|
|
|
|
|
|
def update(source, source_mapper, dest, old_prefix, synchronize_pairs):
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
oldvalue = source_mapper._get_committed_attr_by_column(
|
|
source.obj(), l
|
|
)
|
|
value = source_mapper._get_state_attr_by_column(
|
|
source, source.dict, l, passive=attributes.PASSIVE_OFF
|
|
)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, None, r)
|
|
dest[r.key] = value
|
|
dest[old_prefix + r.key] = oldvalue
|
|
|
|
|
|
def populate_dict(source, source_mapper, dict_, synchronize_pairs):
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
value = source_mapper._get_state_attr_by_column(
|
|
source, source.dict, l, passive=attributes.PASSIVE_OFF
|
|
)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, None, r)
|
|
|
|
dict_[r.key] = value
|
|
|
|
|
|
def source_modified(uowcommit, source, source_mapper, synchronize_pairs):
|
|
"""return true if the source object has changes from an old to a
|
|
new value on the given synchronize pairs
|
|
|
|
"""
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
prop = source_mapper._columntoproperty[l]
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, None, r)
|
|
history = uowcommit.get_attribute_history(
|
|
source, prop.key, attributes.PASSIVE_NO_INITIALIZE
|
|
)
|
|
if bool(history.deleted):
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
|
|
def _raise_col_to_prop(
|
|
isdest, source_mapper, source_column, dest_mapper, dest_column
|
|
):
|
|
if isdest:
|
|
raise exc.UnmappedColumnError(
|
|
"Can't execute sync rule for "
|
|
"destination column '%s'; mapper '%s' does not map "
|
|
"this column. Try using an explicit `foreign_keys` "
|
|
"collection which does not include this column (or use "
|
|
"a viewonly=True relation)." % (dest_column, dest_mapper)
|
|
)
|
|
else:
|
|
raise exc.UnmappedColumnError(
|
|
"Can't execute sync rule for "
|
|
"source column '%s'; mapper '%s' does not map this "
|
|
"column. Try using an explicit `foreign_keys` "
|
|
"collection which does not include destination column "
|
|
"'%s' (or use a viewonly=True relation)."
|
|
% (source_column, source_mapper, dest_column)
|
|
)
|