diff options
Diffstat (limited to 'lib/sqlalchemy')
| -rw-r--r-- | lib/sqlalchemy/orm/persistence.py | 10 | ||||
| -rw-r--r-- | lib/sqlalchemy/orm/session.py | 39 |
2 files changed, 39 insertions, 10 deletions
diff --git a/lib/sqlalchemy/orm/persistence.py b/lib/sqlalchemy/orm/persistence.py index a5e0d9d95..0b029f466 100644 --- a/lib/sqlalchemy/orm/persistence.py +++ b/lib/sqlalchemy/orm/persistence.py @@ -25,7 +25,8 @@ from . import loading def _bulk_insert( - mapper, mappings, session_transaction, isstates, return_defaults): + mapper, mappings, session_transaction, isstates, return_defaults, + render_nulls): base_mapper = mapper.base_mapper cached_connections = _cached_connection_dict(base_mapper) @@ -58,7 +59,8 @@ def _bulk_insert( has_all_defaults in _collect_insert_commands(table, ( (None, mapping, mapper, connection) for mapping in mappings), - bulk=True, return_defaults=return_defaults + bulk=True, return_defaults=return_defaults, + render_nulls=render_nulls ) ) _emit_insert_statements(base_mapper, None, @@ -365,7 +367,7 @@ def _organize_states_for_delete(base_mapper, states, uowtransaction): def _collect_insert_commands( table, states_to_insert, - bulk=False, return_defaults=False): + bulk=False, return_defaults=False, render_nulls=False): """Identify sets of values to use in INSERT statements for a list of states. @@ -384,7 +386,7 @@ def _collect_insert_commands( for propkey in set(propkey_to_col).intersection(state_dict): value = state_dict[propkey] col = propkey_to_col[propkey] - if value is None and propkey not in eval_none: + if value is None and propkey not in eval_none and not render_nulls: continue elif not bulk and isinstance(value, sql.ClauseElement): value_params[col.key] = value diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py index 1cf1bdb24..a7440bf40 100644 --- a/lib/sqlalchemy/orm/session.py +++ b/lib/sqlalchemy/orm/session.py @@ -2261,9 +2261,10 @@ class Session(_SessionClassMethods): ): self._bulk_save_mappings( mapper, states, isupdate, True, - return_defaults, update_changed_only) + return_defaults, update_changed_only, False) - def bulk_insert_mappings(self, mapper, mappings, return_defaults=False): + def bulk_insert_mappings( + self, mapper, mappings, return_defaults=False, render_nulls=False): """Perform a bulk insert of the given list of mapping dictionaries. The bulk insert feature allows plain Python dictionaries to be used as @@ -2316,6 +2317,29 @@ class Session(_SessionClassMethods): reason this flag should be set as the returned default information is not used. + :param render_nulls: When True, a value of ``None`` will result + in a NULL value being included in the INSERT statement, rather + than the column being omitted from the INSERT. This allows all + the rows being INSERTed to have the identical set of columns which + allows the full set of rows to be batched to the DBAPI. Normally, + each column-set that contains a different combination of NULL values + than the previous row must omit a different series of columns from + the rendered INSERT statement, which means it must be emitted as a + separate statement. By passing this flag, the full set of rows + are guaranteed to be batchable into one batch; the cost however is + that server-side defaults which are invoked by an omitted column will + be skipped, so care must be taken to ensure that these are not + necessary. + + .. warning:: + + When this flag is set, **server side default SQL values will + not be invoked** for those columns that are inserted as NULL; + the NULL value will be sent explicitly. Care must be taken + to ensure that no server-side default functions need to be + invoked for the operation as a whole. + + .. versionadded:: 1.1 .. seealso:: @@ -2327,7 +2351,8 @@ class Session(_SessionClassMethods): """ self._bulk_save_mappings( - mapper, mappings, False, False, return_defaults, False) + mapper, mappings, False, False, + return_defaults, False, render_nulls) def bulk_update_mappings(self, mapper, mappings): """Perform a bulk update of the given list of mapping dictionaries. @@ -2376,11 +2401,12 @@ class Session(_SessionClassMethods): :meth:`.Session.bulk_save_objects` """ - self._bulk_save_mappings(mapper, mappings, True, False, False, False) + self._bulk_save_mappings( + mapper, mappings, True, False, False, False, False) def _bulk_save_mappings( self, mapper, mappings, isupdate, isstates, - return_defaults, update_changed_only): + return_defaults, update_changed_only, render_nulls): mapper = _class_to_mapper(mapper) self._flushing = True @@ -2393,7 +2419,8 @@ class Session(_SessionClassMethods): isstates, update_changed_only) else: persistence._bulk_insert( - mapper, mappings, transaction, isstates, return_defaults) + mapper, mappings, transaction, + isstates, return_defaults, render_nulls) transaction.commit() except: |