radloggerpy.database.objects.base module

class radloggerpy.database.objects.base.DatabaseObject(**kwargs)

Bases: object

Abstract database object providing abstract CRUD interfaces

When using SQLAlchemy database sessions all interactions with these sessions should be achieved using objects which implement DatabaseObject. These objects provide CRUD methods to handle interactions allowing to obfuscate that many of the objects in the database are consistent of multiple models.

As an example, to commit an object to the database one would call: DatabaseObject.add(session, object)

Classes implementing these interfaces should implement at least add(), update(), delete() and find(), however, also implementing find_all() and add_all() is preferred.

All reference objects used as parameter by static methods should be instances of the implementing class itself. Likewise, find and find_all should only return objects which are instances of the class itself.

Below is a demonstration of how interactions should look: dbo = DatabaseObject(**{field1: value1, field2: value2}) result = DatabaseObject.find(session, dbo) print(result.field1)

Alternatively the fields can be set after the object is instantiated: dbo = DatabaseObject() dbo.field1 = 'hello world' result = DatabaseObject.find(session, dbo) print(result.field1)

For models using enums or choicetypes the values should be set as object attributes while the keys should be used for internal models.

_abc_impl = <_abc._abc_data object>

abstract _build_attributes()

Build the attributes for the given state of internal models

abstract _build_object()

Build the object with its given attributes for internal models

static _filter(filter_object, ignore=[])

Filters the object depending on it’s set attributes

Removes certain empty objects such as empty collections but not empty strings or byte arrays.

abstract static add(session, reference)

Add the reference object to the database

Parameters:

• session – an active sqlalchemy.orm.session.Session

• reference – add database entries based on this object

abstract static add_all(session, references)

Add all specified objects to the database

Parameters:

• session – an active sqlalchemy.orm.session.Session

• references – add all these objects to the database

abstract static delete(session, reference, allow_multiple=False)

Remove the object(s) that match the reference

Parameters:

• session – an active sqlalchemy.orm.session.Session

• reference – remove database entries based on this object

• allow_multiple – if updating multiple database items is allowed

Raises:

MultipleResultsFound – if multiple results were found with allow_multiple as False of type sqlalchemy.exc.MultipleResultsFound

abstract static find(session, reference, allow_multiple=True)

Return object(s) that match the reference

Parameters:

• session – an active sqlalchemy.orm.session.Session

• reference – find database results based on this object

• allow_multiple – if updating multiple database items is allowed

Raises:

MultipleResultsFound – if multiple results were found with allow_multiple as False of type sqlalchemy.exc.MultipleResultsFound

Returns:

A single object, list of objects or none, all objects will be instances of the class.

abstract static find_all(session, references)

For every specified object find all its matching database objects

Parameters:

• session – an active sqlalchemy.orm.session.Session

• references – find database results based on these objects

Returns:

list of objects or none, all objects will be instances of the class.

abstract static update(session, reference, base, allow_multiple=False)

Find the reference(s) in the database and update with own state

Parameters:

• session – an active sqlalchemy.orm.session.Session

• reference – the object with the desired changes

• base – current state of the object in the database

• allow_multiple – if updating multiple database items is allowed

Raises:

MultipleResultsFound – if multiple results were found with allow_multiple as False of type sqlalchemy.exc.MultipleResultsFound