Function _collect_post_update_commands

lib/sqlalchemy/orm/persistence.py:637–688

Identify sets of values to use in UPDATE statements for a list of states within a post_update operation.

(
    base_mapper, uowtransaction, table, states_to_update, post_update_cols
)

def _collect_post_update_commands(
    base_mapper, uowtransaction, table, states_to_update, post_update_cols
):
    """Identify sets of values to use in UPDATE statements for a
    list of states within a post_update operation.

    """

    for (
        state,
        state_dict,
        mapper,
        connection,
        update_version_id,
    ) in states_to_update:
        # assert table in mapper._pks_by_table

        pks = mapper._pks_by_table[table]
        params = {}
        hasdata = False

        for col in mapper._cols_by_table[table]:
            if col in pks:
                params[col._label] = mapper._get_state_attr_by_column(
                    state, state_dict, col, passive=attributes.PASSIVE_OFF
                )

            elif col in post_update_cols or col.onupdate is not None:
                prop = mapper._columntoproperty[col]
                history = state.manager[prop.key].impl.get_history(
                    state, state_dict, attributes.PASSIVE_NO_INITIALIZE
                )
                if history.added:
                    value = history.added[0]
                    params[col.key] = value
                    hasdata = True
        if hasdata:
            if (
                update_version_id is not None
                and mapper.version_id_col in mapper._cols_by_table[table]
            ):
                col = mapper.version_id_col
                params[col._label] = update_version_id

                if (
                    bool(state.key)
                    and col.key not in params
                    and mapper.version_id_generator is not False
                ):
                    val = mapper.version_id_generator(update_version_id)
                    params[col.key] = val
            yield state, state_dict, mapper, connection, params


def _collect_delete_commands(