def _collect_delete_commands(base_mapper, uowtransaction, table,
states_to_delete):
"""Identify values to use in DELETE statements for a list of
states to be deleted."""
delete = util.defaultdict(list)
for state, state_dict, mapper, has_identity, connection \
in states_to_delete:
if not has_identity or table not in mapper._pks_by_table:
continue
params = {}
delete[connection].append(params)
for col in mapper._pks_by_table[table]:
params[col.key] = \
value = \
mapper._get_state_attr_by_column(
state, state_dict, col)
if value is None:
raise sa_exc.FlushError(
"Can't delete from table "
"using NULL for primary "
"key value")
if mapper.version_id_col is not None and \
table.c.contains_column(mapper.version_id_col):
params[mapper.version_id_col.key] = \
mapper._get_committed_state_attr_by_column(
state, state_dict,
mapper.version_id_col)
return delete
def _collect_update_commands(base_mapper, uowtransaction,
table, states_to_update):
"""Identify sets of values to use in UPDATE statements for a
list of states.
This function works intricately with the history system
to determine exactly what values should be updated
as well as how the row should be matched within an UPDATE
statement. Includes some tricky scenarios where the primary
key of an object might have been changed.
"""
update = []
for state, state_dict, mapper, connection, has_identity, \
instance_key, row_switch in states_to_update:
if table not in mapper._pks_by_table:
continue
pks = mapper._pks_by_table[table]
params = {}
value_params = {}
hasdata = hasnull = False
for col in mapper._cols_by_table[table]:
if col is mapper.version_id_col:
params[col._label] = \
mapper._get_committed_state_attr_by_column(
row_switch or state,
row_switch and row_switch.dict
or state_dict,
col)
prop = mapper._columntoproperty[col]
history = attributes.get_state_history(
state, prop.key,
attributes.PASSIVE_NO_INITIALIZE
)
if history.added:
params[col.key] = history.added[0]
hasdata = True
else:
params[col.key] = mapper.version_id_generator(
params[col._label])
# HACK: check for history, in case the
# history is only
# in a different table than the one
# where the version_id_col is.
for prop in mapper._columntoproperty.itervalues():
history = attributes.get_state_history(
state, prop.key,
attributes.PASSIVE_NO_INITIALIZE)
if history.added:
hasdata = True
else:
prop = mapper._columntoproperty[col]
history = attributes.get_state_history(
state, prop.key,
attributes.PASSIVE_NO_INITIALIZE)
if history.added:
if isinstance(history.added[0],
sql.ClauseElement):
value_params[col] = history.added[0]
else:
value = history.added[0]
params[col.key] = value
if col in pks:
if history.deleted and \
not row_switch:
# if passive_updates and sync detected
# this was a pk->pk sync, use the new
# value to locate the row, since the
# DB would already have set this
if ("pk_cascaded", state, col) in \
uowtransaction.attributes:
value = history.added[0]
params[col._label] = value
else:
# use the old value to
# locate the row
value = history.deleted[0]
params[col._label] = value
hasdata = True
else:
# row switch logic can reach us here
# remove the pk from the update params
# so the update doesn't
# attempt to include the pk in the
# update statement
del params[col.key]
value = history.added[0]
params[col._label] = value
if value is None:
hasnull = True
else:
hasdata = True
elif col in pks:
value = state.manager[prop.key].impl.get(
state, state_dict)
if value is None:
hasnull = True
params[col._label] = value
if hasdata:
if hasnull:
raise sa_exc.FlushError(
"Can't update table "
"using NULL for primary "
"key value")
update.append((state, state_dict, params, mapper,
connection, value_params))
return update
