Method _init_from_db

tortoise/models.py:813–856

(cls: type[MODEL], **kwargs: Any)

    @classmethod
    def _init_from_db(cls: type[MODEL], **kwargs: Any) -> MODEL:
        self = cls.__new__(cls)
        self._partial = False
        self._saved_in_db = True
        self._custom_generated_pk = self._meta.db_pk_column not in self._meta.generated_db_fields
        self._await_when_save = {}

        meta = self._meta
        _setattr = object.__setattr__  # bypass __setattr__ override for performance
        try:
            # This is like so for performance reasons.
            #  We want to avoid conditionals and calling .to_python_value()
            # Native fields are fields that are already converted to/from python to DB type
            #  by the DB driver
            for key, model_field, field in meta.db_native_fields:
                _setattr(self, model_field, kwargs[key])
            # Fields that don't override .to_python_value() are converted without a call
            #  as we already know what we will be doing.
            for key, model_field, field in meta.db_default_fields:
                if (value := kwargs[key]) is not None:
                    value = field.field_type(value)
                _setattr(self, model_field, value)
            # These fields need manual .to_python_value()
            for key, model_field, field in meta.db_complex_fields:
                _setattr(self, model_field, field.to_python_value(kwargs[key]))
        except KeyError:
            # Partial model (.only() query) — slower but correct fallback
            self._partial = True
            native_keys = {k for k, _, _ in meta.db_native_fields}
            default_keys = {k for k, _, _ in meta.db_default_fields}
            for key, value in kwargs.items():
                if key not in meta.fields_map:
                    continue
                field = meta.fields_map[key]
                if key not in native_keys:
                    if key in default_keys:
                        if value is not None:
                            value = field.field_type(value)
                    else:
                        value = field.to_python_value(value)
                model_field = meta.fields_db_projection_reverse.get(key, key)
                _setattr(self, model_field, value)

        return self

    def __str__(self) -> str:
        return f"<{self.__class__.__name__}>"