API Reference

marshmallow_sqlalchemy.fields_for_model =func(...)

Generate a dict of field_name: marshmallow.fields.Field pairs for the given model.

Parameters:

• model – The SQLAlchemy model
• include_fk (bool) – Whether to include foreign key fields in the output.

Returns:

dict of field_name: Field instance pairs

marshmallow_sqlalchemy.property2field =func(...)

Convert a SQLAlchemy Property to a field instance or class.

Parameters:

• prop (Property) – SQLAlchemy Property.
• instance (bool) – If True, return Field instance, computing relevant kwargs from the given property. If False, return the Field class.
• kwargs – Additional keyword arguments to pass to the field constructor.

Returns:

A marshmallow.fields.Field class or instance.

marshmallow_sqlalchemy.column2field =func(...)

Convert a SQLAlchemy Column to a field instance or class.

Parameters:

• column (sqlalchemy.schema.Column) – SQLAlchemy Column.
• instance (bool) – If True, return Field instance, computing relevant kwargs from the given property. If False, return the Field class.

Returns:

A marshmallow.fields.Field class or instance.

marshmallow_sqlalchemy.field_for =func(...)

Convert a property for a mapped SQLAlchemy class to a marshmallow Field. Example:

date_created = field_for(Author, 'date_created', dump_only=True)
author = field_for(Book, 'author')

Parameters:

• model (type) – A SQLAlchemy mapped class.
• property_name (str) – The name of the property to convert.
• kwargs – Extra keyword arguments to pass to property2field

Returns:

A marshmallow.fields.Field class or instance.

class marshmallow_sqlalchemy.TableSchema(only=(), exclude=(), prefix='', strict=None, many=False, context=None, load_only=(), dump_only=(), partial=False)

Base class for SQLAlchemy model-based Schemas.

Example:

from marshmallow_sqlalchemy import TableSchema
from mymodels import engine, users

class UserSchema(TableSchema):
    class Meta:
        table = users

schema = UserSchema()

select = users.select().limit(1)
user = engine.execute(select).fetchone()
serialized = schema.dump(user).data

OPTIONS_CLASS

alias of TableSchemaOpts

class marshmallow_sqlalchemy.ModelSchema(*args, **kwargs)

Base class for SQLAlchemy model-based Schemas.

Example:

from marshmallow_sqlalchemy import ModelSchema
from mymodels import User, session

class UserSchema(ModelSchema):
    class Meta:
        model = User

schema = UserSchema()

user = schema.load({'name': 'Bill'}, session=session)
existing_user = schema.load({'name': 'Bill'}, instance=User.query.first())

Parameters:

• session – Optional SQLAlchemy session; may be overridden in load.
• instance – Optional existing instance to modify; may be overridden in load.

OPTIONS_CLASS

alias of ModelSchemaOpts

get_instance(data)

Retrieve an existing record by primary key(s).

load(data, session=None, instance=None, *args, **kwargs)

Deserialize data to internal representation.

Parameters:

• session – Optional SQLAlchemy session.
• instance – Optional existing instance to modify.

make_instance(data)

Deserialize data to an instance of the model. Update an existing row if specified in self.instance or loaded by primary key(s) in the data; else create a new row.

Parameters:data – Data to deserialize.

validate(data, session=None, *args, **kwargs)

Validate data against the schema, returning a dictionary of validation errors.

Parameters:

• data (dict) – The data to validate.
• many (bool) – Whether to validate data as a collection. If None, the value for self.many is used.
• partial (bool|tuple) – Whether to ignore missing fields. If None, the value for self.partial is used. If its value is an iterable, only missing fields listed in that iterable will be ignored.

Returns:

A dictionary of validation errors.

Return type:

dict

New in version 1.1.0.

class marshmallow_sqlalchemy.TableSchemaOpts(meta, *args, **kwargs)

Options class for TableSchema. Adds the following options:

• table: The SQLAlchemy table to generate the Schema from (required).

• model_converter: ModelConverter class to use for converting the SQLAlchemy table to

  marshmallow fields.

• include_fk: Whether to include foreign fields; defaults to False.

class marshmallow_sqlalchemy.ModelSchemaOpts(meta, *args, **kwargs)

Options class for ModelSchema. Adds the following options:

• model: The SQLAlchemy model to generate the Schema from (required).

• sqla_session: SQLAlchemy session to be used for deserialization. This is optional; you

  can also pass a session to the Schema’s load method.

• model_converter: ModelConverter class to use for converting the SQLAlchemy model to

  marshmallow fields.

• include_fk: Whether to include foreign fields; defaults to False.

class marshmallow_sqlalchemy.ModelConverter(schema_cls=None)

Class that converts a SQLAlchemy model into a dictionary of corresponding marshmallow Fields.

exception marshmallow_sqlalchemy.ModelConversionError

Raised when an error occurs in converting a SQLAlchemy construct to a marshmallow object.