Data model¶

This page is a reference for the database models. It covers each model's purpose, its meaningful fields, its relationships, and the constraints that the database enforces. Field names match the source exactly; the model files are linked from each section.

Everything is scoped to an Event. Talks, rooms, tickets, and pending Pretalx changes all point back to an event, and access control filters on it (see the multi-event design).

Entity relationships¶

erDiagram
    Event ||--o{ Talk : "has"
    Event ||--o{ Room : "has"
    Event ||--o{ Ticket : "sold for"
    Event ||--o{ PendingPretalxChange : "tracks"
    Event }o--o{ CustomUser : "membership"

    Room ||--o{ Talk : "hosts"
    Room ||--o{ Streaming : "streams"

    Talk }o--o{ Speaker : "presented by"
    Talk ||--o{ Rating : "rated by"
    Talk ||--o{ SavedTalk : "bookmarked as"
    Talk ||--o{ Question : "asked about"
    CustomUser ||--o{ Talk : "chairs"

    Question ||--o{ QuestionVote : "voted on"
    Question ||--o{ Answer : "answered by"

    CustomUser ||--o{ Rating : "writes"
    CustomUser ||--o{ SavedTalk : "saves"
    CustomUser ||--o{ Ticket : "holds"
    CustomUser ||--o{ Question : "asks"
    CustomUser ||--o{ QuestionVote : "casts"
    CustomUser ||--o{ Answer : "gives"

events app¶

Source: events/models.py

Event¶

A single conference event, for example "PyCon DE & PyData 2026". One deployment holds several.

Key fields:

name - unique display name (include the year if relevant).
slug - unique slug used in URLs and to organize per-event assets and media. Not necessarily the same as the Pretalx slug.
year - optional, validated to the range 2000-2100.
is_active - whether the event is visible on the site. Inactive events are filtered out of event resolution and access checks.
validation_api_url - external API that confirms a user bought a ticket for this event; blank disables API validation.
show_rating_summary - whether regular users see the average rating and count. Staff and superusers always see summaries.
Branding URLs: main_website_url, imprint_url, code_of_conduct_url, privacy_policy_url, venue_url, transcriptions_url, plus logo_svg_name, made_by_name, made_by_url.
pretalx_url - the Pretalx event base URL. The properties pretalx_schedule_url and pretalx_speakers_url derive the schedule and speaker pages from it.

Relationships: reverse talks, rooms, tickets, pending_pretalx_changes, and users (many-to-many with CustomUser).

talks app¶

Source: talks/models.py, models_rating.py, models_qa.py, models_pretalx.py

Room¶

A room where talks happen. Rooms are event-scoped, not global.

Key fields: event (required, on_delete=PROTECT), name, pretalx_id (the stable Pretalx slot.room.id; null for manually created or legacy rooms), description, capacity, and slido_link.

Room constraints

uniq_room_event_name: room names are unique per event, not globally. The same name can exist under different events.
uniq_room_event_pretalx_id: at most one room per Pretalx id per event. The constraint is partial (pretalx_id IS NOT NULL) so legacy and manual rooms with a null id do not collide.

Room.resolve_for_event() is the shared matcher: it looks up (event, pretalx_id) first (the key that survives a rename on Pretalx), then falls back to (event, name) for legacy rows.

Streaming¶

A live streaming session bound to a room and a time window.

Key fields: room (on_delete=CASCADE), start_time, end_time, video_link, and transcription_url.

Constraints and behavior: a check constraint (streaming_start_before_end) enforces start_time < end_time, and clean() rejects overlapping streamings for the same room. A talk is matched to the streaming that covers its slot (at least half the talk inside the window, allowing a one-minute start margin), which is how unrecorded talks fall back to the room's live stream.

Speaker¶

A conference speaker.

Key fields: name, biography, avatar (URL), optional gender (text choices) with gender_self_description, pronouns, and pretalx_id (unique, the match key for imports).

Relationships: many-to-many with Talk (reverse talks).

Talk¶

A conference talk. This is the central model.

Key fields:

presentation_type - one of Keynote, Kids, Lightning, Open Space, Panel, Plenary, Talk, Tutorial. Drives the default duration and track.
title, abstract, description.
speakers - many-to-many with Speaker.
start_time - defaults to a FAR_FUTURE sentinel (year 2050) for talks not yet scheduled. TalkQuerySet.scheduled() excludes those.
duration - a DurationField; defaults from the presentation type when left blank.
end_time - derived as start_time + duration and stored so it can be indexed. Set automatically by apply_derived_defaults() on every save; never written by hand.
room - foreign key (on_delete=SET_NULL); a talk's room must belong to the same event.
track - defaults to "No track", or "Lightning Talks" for lightning talks.
external_image_url and image - the uploaded image wins over the external URL; both fall back to a per-event placeholder.
pretalx_link - the Pretalx talk page; pretalx_code parses the submission code out of it.
slido_link, video_link (validated, YouTube links get enablejsapi=1 appended), transcription_url, video_start_time.
event - required (on_delete=CASCADE).
session_chair - optional foreign key to CustomUser (on_delete=SET_NULL); the volunteer moderating the session.
hide - hides the talk from the public.
created_at, updated_at.

Validation: clean() rejects a room from a different event and any talk that overlaps another in the same room. The model carries a rich set of indexes for the common list and schedule queries (by start time, room, event, presentation type, and the hide/start_time and end_time combinations).

TalkQuerySet adds the access and aggregation helpers used across views: accessible_to(user), scheduled(), with_streamings() (batch-loads the streaming cache to avoid N+1), and with_rating_stats() (annotates average_rating and rating_count).

Rating¶

A user's 1-to-5 score for a talk, with an optional admin-only comment.

Key fields: talk (on_delete=CASCADE), user (on_delete=CASCADE), score (PositiveSmallIntegerField), comment (free text, max 2000 characters, visible only to admins), created_at, updated_at.

Rating constraints

unique_user_talk_rating: one rating per user per talk. Re-rating updates the existing row.
rating_score_range: a check constraint enforcing 1 <= score <= 5.

SavedTalk¶

A user's bookmark of a talk.

Key fields: user (on_delete=CASCADE), talk (on_delete=CASCADE), created_at. The unique_user_saved_talk constraint keeps one bookmark per (user, talk). SavedTalk.talk_ids_for(user) returns the set of saved talk ids for fast membership checks in list templates.

Question¶

A question asked about a talk. Part of the live Q&A feature.

Key fields: talk (on_delete=CASCADE), content (max 2000 characters), user (on_delete=SET_NULL, nullable so anonymous questions survive a user deletion), status (one of approved, answered, rejected; defaults to approved), created_at, updated_at.

QuestionQuerySet provides with_vote_count(), sorted_by_votes(), approved(), answered(), and not_rejected(). The display_name property obfuscates the author's email for the public author line.

QuestionVote¶

An upvote on a question.

Key fields: question (on_delete=CASCADE), user (on_delete=CASCADE), created_at. The unique_question_vote constraint enforces one vote per (question, user).

Answer¶

An answer to a question, typically from a speaker or moderator.

Key fields: question (on_delete=CASCADE), content (max 2000 characters), user (on_delete=SET_NULL), is_official (flags a speaker or organizer answer), created_at, updated_at.

Saving an answer flips the parent question to answered unless it was already rejected.

PendingPretalxChange¶

A diff the Pretalx importer detected in --detect-only mode but has not applied to live data. Admins review these and apply or dismiss them. See the Pretalx sync manual for the workflow.

Key fields:

event (on_delete=CASCADE) and pretalx_code - the submission this change concerns.
talk - the local talk it targets (on_delete=SET_NULL, null for a CREATE).
kind - create, update, or delete.
field_diffs - per-field {field: {old, new}} JSON; empty for create/delete.
speaker_diffs - speaker many-to-many JSON {added: [...], removed: [...]}.
pretalx_payload - a self-contained snapshot of the new values, so applying does not need a fresh Pretalx fetch.
first_detected_at, last_detected_at, applied_at/applied_by, dismissed_at/dismissed_by.

Pending-change constraint

unique_open_pending_change_per_submission: at most one open (neither applied nor dismissed) row per (event, pretalx_code). The constraint is partial (applied_at IS NULL AND dismissed_at IS NULL). Re-detecting the same diff updates the existing open row and bumps last_detected_at instead of creating duplicates; a fresh detection after a row is applied or dismissed creates a new open row.

A row is "pending" while is_pending is true (both timestamps null). mark_applied() and mark_dismissed() stamp the matching timestamp and author.

users app¶

Source: users/models.py

CustomUser¶

An email-based user. There is no username field. Login is passwordless for regular users (emailed one-time codes); only superusers carry a real password.

Key fields:

email - unique, normalized to lowercase, used as USERNAME_FIELD.
display_name - optional public name shown when asking questions; validated.
events - many-to-many with Event, listing the events the user may access.

save() enforces the password rule (superusers must have one, regular users must not). label(obfuscate=...) returns the best human-readable name (display name, then full name, then email), masking the email when used in public contexts. visible_events() returns the active events the user may see.

Ticket¶

Links a user to an event by a unique ticket id, recording proof that the user holds a ticket for that event.

Key fields: user (on_delete=CASCADE), event (on_delete=CASCADE), ticket_id, created_at. The unique_ticket_per_event constraint keeps each ticket id unique within an event.