How to use the indico.core.db.db.ForeignKey function in indico

#: Whether to show a ticket download link on the event homepage
    ticket_on_event_page = db.Column(
        db.Boolean,
        nullable=False,
        default=True
    )
    #: Whether to show a ticket download link on the registration summary page
    ticket_on_summary_page = db.Column(
        db.Boolean,
        nullable=False,
        default=True
    )
    #: The ID of the template used to generate tickets
    ticket_template_id = db.Column(
        db.Integer,
        db.ForeignKey(DesignerTemplate.id),
        nullable=True,
        index=True
    )

    #: The Event containing this registration form
    event = db.relationship(
        'Event',
        lazy=True,
        backref=db.backref(
            'registration_forms',
            primaryjoin='(RegistrationForm.event_id == Event.id) & ~RegistrationForm.is_deleted',
            cascade='all, delete-orphan',
            lazy=True
        )
    )
    #: The template used to generate tickets

)
    #: ID of the videoconference room
    vc_room_id = db.Column(
        db.Integer,
        db.ForeignKey('events.vc_rooms.id'),
        index=True,
        nullable=False
    )
    #: Type of the object the vc_room is linked to
    link_type = db.Column(
        PyIntEnum(VCRoomLinkType),
        nullable=False
    )
    linked_event_id = db.Column(
        db.Integer,
        db.ForeignKey('events.events.id'),
        index=True,
        nullable=True
    )
    session_block_id = db.Column(
        db.Integer,
        db.ForeignKey('events.session_blocks.id'),
        index=True,
        nullable=True
    )
    contribution_id = db.Column(
        db.Integer,
        db.ForeignKey('events.contributions.id'),
        index=True,
        nullable=True
    )
    #: If the vc room should be shown on the event page

schema='roombooking'
)

ReservationEquipmentAssociation = db.Table(
    'reservation_equipment',
    db.metadata,
    db.Column(
        'equipment_id',
        db.Integer,
        db.ForeignKey('roombooking.equipment_types.id'),
        primary_key=True,
    ),
    db.Column(
        'reservation_id',
        db.Integer,
        db.ForeignKey('roombooking.reservations.id'),
        primary_key=True
    ),
    schema='roombooking'
)


class EquipmentType(db.Model):
    __tablename__ = 'equipment_types'
    __table_args__ = (db.UniqueConstraint('name', 'location_id'),
                      {'schema': 'roombooking'})

    id = db.Column(
        db.Integer,
        primary_key=True
    )
    parent_id = db.Column(

'polymorphic_on': 'type',
        'polymorphic_identity': None
    }

    possible_render_modes = {RenderMode.markdown}
    default_render_mode = RenderMode.markdown

    #: The ID of the item
    id = db.Column(
        db.Integer,
        primary_key=True
    )
    #: The ID of the survey
    survey_id = db.Column(
        db.Integer,
        db.ForeignKey('event_surveys.surveys.id'),
        index=True,
        nullable=False,
    )
    #: The ID of the parent section item (NULL for top-level items, i.e. sections)
    parent_id = db.Column(
        db.Integer,
        db.ForeignKey('event_surveys.items.id'),
        index=True,
        nullable=True,
    )
    #: The position of the item in the survey form
    position = db.Column(
        db.Integer,
        nullable=False,
        default=_get_next_position
    )

class BlockingPrincipal(PrincipalMixin, db.Model):
    __tablename__ = 'blocking_principals'
    principal_backref_name = 'in_blocking_acls'
    unique_columns = ('blocking_id',)

    @declared_attr
    def __table_args__(cls):
        return auto_table_args(cls, schema='roombooking')

    id = db.Column(
        db.Integer,
        primary_key=True
    )
    blocking_id = db.Column(
        db.Integer,
        db.ForeignKey('roombooking.blockings.id'),
        nullable=False
    )

    # relationship backrefs:
    # - blocking (Blocking._allowed)

    @return_ascii
    def __repr__(self):
        return ''.format(
            self.id,
            self.blocking_id,
            self.principal
        )

class EditableType(int, IndicoEnum):
    paper = 1
    slides = 2


class Editable(db.Model):
    __tablename__ = 'editables'
    __table_args__ = (db.UniqueConstraint('contribution_id', 'type'),
                      {'schema': 'event_editing'})

    id = db.Column(
        db.Integer,
        primary_key=True
    )
    contribution_id = db.Column(
        db.ForeignKey('events.contributions.id'),
        index=True,
        nullable=False
    )
    type = db.Column(
        PyIntEnum(EditableType),
        nullable=False
    )
    editor_id = db.Column(
        db.ForeignKey('users.users.id'),
        index=True,
        nullable=True
    )
    published_revision_id = db.Column(
        db.ForeignKey('event_editing.revisions.id'),
        index=True,
        nullable=True

from indico.util.string import return_ascii


class UserAffiliation(db.Model):
    __tablename__ = 'affiliations'
    __table_args__ = {'schema': 'users'}

    #: the unique id of the affiliations
    id = db.Column(
        db.Integer,
        primary_key=True
    )
    #: the id of the associated user
    user_id = db.Column(
        db.Integer,
        db.ForeignKey('users.users.id'),
        nullable=False,
        index=True
    )

    #: the affiliation
    name = db.Column(
        db.String,
        nullable=False,
        index=True
    )

    # relationship backrefs:
    # - user (User._affiliation)

    @return_ascii
    def __repr__(self):

#: The ID of the revision
    id = db.Column(
        db.Integer,
        primary_key=True
    )
    #: The ID of the associated note
    note_id = db.Column(
        db.Integer,
        db.ForeignKey('events.notes.id'),
        nullable=False,
        index=True
    )
    #: The user who created the revision
    user_id = db.Column(
        db.Integer,
        db.ForeignKey('users.users.id'),
        nullable=False,
        index=True
    )
    #: The date/time when the revision was created
    created_dt = db.Column(
        UTCDateTime,
        nullable=False,
        default=now_utc
    )
    #: How the note is rendered
    render_mode = db.Column(
        PyIntEnum(RenderMode),
        nullable=False
    )
    #: The raw source of the note as provided by the user
    source = db.Column(

# Indico is free software; you can redistribute it and/or
# modify it under the terms of the MIT License; see the
# LICENSE file for more details.

from __future__ import unicode_literals

from indico.core.db import db


favorite_room_table = db.Table(
    'favorite_rooms',
    db.metadata,
    db.Column(
        'user_id',
        db.Integer,
        db.ForeignKey('users.users.id'),
        primary_key=True,
        nullable=False,
        index=True
    ),
    db.Column(
        'room_id',
        db.Integer,
        db.ForeignKey('roombooking.rooms.id'),
        primary_key=True,
        nullable=False,
        index=True
    ),
    schema='roombooking'
)

id = db.Column(
        db.Integer,
        primary_key=True
    )
    contribution_id = db.Column(
        db.ForeignKey('events.contributions.id'),
        index=True,
        nullable=False
    )
    type = db.Column(
        PyIntEnum(EditableType),
        nullable=False
    )
    editor_id = db.Column(
        db.ForeignKey('users.users.id'),
        index=True,
        nullable=True
    )
    published_revision_id = db.Column(
        db.ForeignKey('event_editing.revisions.id'),
        index=True,
        nullable=True
    )

    contribution = db.relationship(
        'Contribution',
        lazy=True,
        backref=db.backref(
            'editables',
            lazy=True,
        )