ormar/docs/api/models/new-basemodel.md

models.newbasemodel

NewBaseModel Objects

class NewBaseModel(pydantic.BaseModel,  ModelTableProxy, metaclass=ModelMetaclass)

Main base class of ormar Model. Inherits from pydantic BaseModel and has all mixins combined in ModelTableProxy. Constructed with ModelMetaclass which in turn also inherits pydantic metaclass.

Abstracts away all internals and helper functions, so final Model class has only the logic concerned with database connection and data persistance.

__init__

 | __init__(*args: Any, **kwargs: Any) -> None

Initializer that creates a new ormar Model that is also pydantic Model at the same time.

Passed keyword arguments can be only field names and their corresponding values as those will be passed to pydantic validation that will complain if extra params are passed.

If relations are defined each relation is expanded and children models are also initialized and validated. Relation from both sides is registered so you can access related models from both sides.

Json fields are automatically loaded/dumped if needed.

Models marked as abstract=True in internal Meta class cannot be initialized.

Accepts also special pk_only flag that indicates that Model is constructed only with primary key value (so no other fields, it's a child model on other Model), that causes skipping the validation, that's the only case when the validation can be skipped.

Accepts also special excluded parameter that contains a set of fields that should be explicitly set to None, as otherwise pydantic will try to populate them with their default values if default is set.

Raises:

• ModelError: if abstract model is initialized, model has ForwardRefs that has not been updated or unknown field is passed

Arguments:

• args (Any): ignored args
• kwargs (Any): keyword arguments - all fields values and some special params

__setattr__

 | __setattr__(name: str, value: Any) -> None

Overwrites setattr in object to allow for special behaviour of certain params.

Parameter "pk" is translated into actual primary key field name.

Relations are expanded (child model constructed if needed) and registered on both ends of the relation. The related models are handled by RelationshipManager exposed at _orm param.

Json fields converted if needed.

Setting pk, foreign key value or any other field value sets Model save status to False. Setting a reverse relation or many to many relation does not as it does not modify the state of the model (but related model or through model).

To short circuit all checks and expansions the set of attribute names present on each model is gathered into _quick_access_fields that is looked first and if field is in this set the object setattr is called directly.

Arguments:

• name (str): name of the attribute to set
• value (Any): value of the attribute to set

Returns:

(None): None

__getattribute__

 | __getattribute__(item: str) -> Any

Because we need to overwrite getting the attribute by ormar instead of pydantic as well as returning related models and not the value stored on the model the getattribute needs to be used not getattr.

It's used to access all attributes so it can be a big overhead that's why a number of short circuits is used.

To short circuit all checks and expansions the set of attribute names present on each model is gathered into _quick_access_fields that is looked first and if field is in this set the object setattr is called directly.

To avoid recursion object's getattribute is used to actually get the attribute value from the model after the checks.

Even the function calls are constructed with objects functions.

Parameter "pk" is translated into actual primary key field name.

Relations are returned so the actual related model is returned and not current model's field. The related models are handled by RelationshipManager exposed at _orm param.

Json fields are converted if needed.

Arguments:

• item (str): name of the attribute to retrieve

Returns:

(Any): value of the attribute

_verify_model_can_be_initialized

 | _verify_model_can_be_initialized() -> None

Raises exception if model is abstract or has ForwardRefs in relation fields.

Returns:

(None): None

_extract_related_model_instead_of_field

 | _extract_related_model_instead_of_field(item: str) -> Optional[Union["Model", Sequence["Model"]]]

Retrieves the related model/models from RelationshipManager.

Arguments:

• item (str): name of the relation

Returns:

(Optional[Union[Model, List[Model]]]): related model, list of related models or None

__eq__

 | __eq__(other: object) -> bool

Compares other model to this model. when == is called.

Arguments:

• other (object): other model to compare

Returns:

(bool): result of comparison

__same__

 | __same__(other: "NewBaseModel") -> bool

Used by eq, compares other model to this model. Compares:

• _orm_ids,
• primary key values if it's set
• dictionary of own fields (excluding relations)

Arguments:

• other (NewBaseModel): model to compare to

Returns:

(bool): result of comparison

get_name

 | @classmethod
 | get_name(cls, lower: bool = True) -> str

Returns name of the Model class, by default lowercase.

Arguments:

• lower (bool): flag if name should be set to lowercase

Returns:

(str): name of the model

pk_column

 | @property
 | pk_column() -> sqlalchemy.Column

Retrieves primary key sqlalchemy column from models Meta.table. Each model has to have primary key. Only one primary key column is allowed.

Returns:

(sqlalchemy.Column): primary key sqlalchemy column

saved

 | @property
 | saved() -> bool

Saved status of the model. Changed by setattr and loading from db

signals

 | @property
 | signals() -> "SignalEmitter"

Exposes signals from model Meta

pk_type

 | @classmethod
 | pk_type(cls) -> Any

Shortcut to models primary key field type

db_backend_name

 | @classmethod
 | db_backend_name(cls) -> str

Shortcut to database dialect, cause some dialect require different treatment

remove

 | remove(parent: "Model", name: str) -> None

Removes child from relation with given name in RelationshipManager

set_save_status

 | set_save_status(status: bool) -> None

Sets value of the save status

get_properties

 | @classmethod
 | get_properties(cls, include: Union[Set, Dict, None], exclude: Union[Set, Dict, None]) -> Set[str]

Returns a set of names of functions/fields decorated with @property_field decorator.

They are added to dictionary when called directly and therefore also are present in fastapi responses.

Arguments:

• include (Union[Set, Dict, None]): fields to include
• exclude (Union[Set, Dict, None]): fields to exclude

Returns:

(Set[str]): set of property fields names

update_forward_refs

 | @classmethod
 | update_forward_refs(cls, **localns: Any) -> None

Processes fields that are ForwardRef and need to be evaluated into actual models.

Expands relationships, register relation in alias manager and substitutes sqlalchemy columns with new ones with proper column type (null before).

Populates Meta table of the Model which is left empty before.

Sets self_reference flag on models that links to themselves.

Calls the pydantic method to evaluate pydantic fields.

Arguments:

• localns (Any): local namespace

Returns:

(None): None

_get_related_not_excluded_fields

 | _get_related_not_excluded_fields(include: Optional[Dict], exclude: Optional[Dict]) -> List

Returns related field names applying on them include and exclude set.

Arguments:

• include (Union[Set, Dict, None]): fields to include
• exclude (Union[Set, Dict, None]): fields to exclude

Returns:

(List of fields with relations that is not excluded):

_extract_nested_models_from_list

 | @staticmethod
 | _extract_nested_models_from_list(relation_map: Dict, models: MutableSequence, include: Union[Set, Dict, None], exclude: Union[Set, Dict, None]) -> List

Converts list of models into list of dictionaries.

Arguments:

• models (List): List of models
• include (Union[Set, Dict, None]): fields to include
• exclude (Union[Set, Dict, None]): fields to exclude

Returns:

(List[Dict]): list of models converted to dictionaries

_skip_ellipsis

 | _skip_ellipsis(items: Union[Set, Dict, None], key: str, default_return: Any = None) -> Union[Set, Dict, None]

Helper to traverse the include/exclude dictionaries. In dict() Ellipsis should be skipped as it indicates all fields required and not the actual set/dict with fields names.

Arguments:

• items (Union[Set, Dict, None]): current include/exclude value
• key (str): key for nested relations to check

Returns:

(Union[Set, Dict, None]): nested value of the items

_convert_all

 | _convert_all(items: Union[Set, Dict, None]) -> Union[Set, Dict, None]

Helper to convert all pydantic special index to ormar which does not support index based exclusions.

Arguments:

• items (Union[Set, Dict, None]): current include/exclude value

_extract_nested_models

 | _extract_nested_models(relation_map: Dict, dict_instance: Dict, include: Optional[Dict], exclude: Optional[Dict]) -> Dict

Traverse nested models and converts them into dictionaries. Calls itself recursively if needed.

Arguments:

• nested (bool): flag if current instance is nested
• dict_instance (Dict): current instance dict
• include (Optional[Dict]): fields to include
• exclude (Optional[Dict]): fields to exclude

Returns:

(Dict): current model dict with child models converted to dictionaries

dict

 | dict(*, include: Union[Set, Dict] = None, exclude: Union[Set, Dict] = None, by_alias: bool = False, skip_defaults: bool = None, exclude_unset: bool = False, exclude_defaults: bool = False, exclude_none: bool = False, relation_map: Dict = None) -> "DictStrAny"

Generate a dictionary representation of the model, optionally specifying which fields to include or exclude.

Nested models are also parsed to dictionaries.

Additionally fields decorated with @property_field are also added.

Arguments:

• include (Union[Set, Dict, None]): fields to include
• exclude (Union[Set, Dict, None]): fields to exclude
• by_alias (bool): flag to get values by alias - passed to pydantic
• skip_defaults (bool): flag to not set values - passed to pydantic
• exclude_unset (bool): flag to exclude not set values - passed to pydantic
• exclude_defaults (bool): flag to exclude default values - passed to pydantic
• exclude_none (bool): flag to exclude None values - passed to pydantic
• relation_map (Dict): map of the relations to follow to avoid circural deps

Returns:

():

update_from_dict

 | update_from_dict(value_dict: Dict) -> "NewBaseModel"

Updates self with values of fields passed in the dictionary.

Arguments:

• value_dict (Dict): dictionary of fields names and values

Returns:

(NewBaseModel): self

_convert_json

 | _convert_json(column_name: str, value: Any, op: str) -> Union[str, Dict]

Converts value to/from json if needed (for Json columns).

Arguments:

• column_name (str): name of the field
• value (Any): value fo the field
• op (str): operator on json

Returns:

(Any): converted value if needed, else original value

_is_conversion_to_json_needed

 | _is_conversion_to_json_needed(column_name: str) -> bool

Checks if given column name is related to JSON field.

Arguments:

• column_name (str): name of the field

Returns:

(bool): result of the check

_extract_own_model_fields

 | _extract_own_model_fields() -> Dict

Returns a dictionary with field names and values for fields that are not relations fields (ForeignKey, ManyToMany etc.)

Returns:

(Dict): dictionary of fields names and values.

_extract_model_db_fields

 | _extract_model_db_fields() -> Dict

Returns a dictionary with field names and values for fields that are stored in current model's table.

That includes own non-relational fields ang foreign key fields.

Returns:

(Dict): dictionary of fields names and values.

get_relation_model_id

 | get_relation_model_id(target_field: "BaseField") -> Optional[int]

Returns an id of the relation side model to use in prefetch query.

Arguments:

• target_field ("BaseField"): field with relation definition

Returns:

(Optional[int]): value of pk if set