# Database Schema (DuckDB) — extracted DDL

## Rules
- Use DuckDB for persistent storage when available; fallback to JSON files when duckdb is not installed (database.py). 
- Keep schema migrations additive (ALTER TABLE ADD COLUMN IF NOT EXISTS used in database.py).

## Examples (DDL snippets extracted from database.py)

### motions table
```sql
CREATE TABLE IF NOT EXISTS motions (
    id INTEGER DEFAULT nextval('motions_id_seq'),
    title TEXT NOT NULL,
    description TEXT,
    date DATE,
    policy_area TEXT,
    voting_results JSON,
    winning_margin FLOAT,
    controversy_score FLOAT,
    layman_explanation TEXT,
    externe_identifier TEXT,
    body_text TEXT,
    url TEXT UNIQUE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (id)
)
```

### mp_votes table
```sql
CREATE TABLE IF NOT EXISTS mp_votes (
    id INTEGER DEFAULT nextval('mp_votes_id_seq'),
    motion_id INTEGER NOT NULL,
    mp_name TEXT NOT NULL,
    party TEXT,
    vote TEXT NOT NULL,
    date DATE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (id)
)
```

### embeddings / fused_embeddings
```sql
CREATE TABLE IF NOT EXISTS embeddings (
    id INTEGER DEFAULT nextval('embeddings_id_seq'),
    motion_id INTEGER NOT NULL,
    model TEXT,
    vector JSON NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (id)
)

CREATE TABLE IF NOT EXISTS fused_embeddings (
    id INTEGER DEFAULT nextval('fused_embeddings_id_seq'),
    motion_id INTEGER NOT NULL,
    window_id TEXT NOT NULL,
    vector JSON NOT NULL,
    svd_dims INTEGER NOT NULL,
    text_dims INTEGER NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (id)
)
```

## Anti-patterns
- Broad try/except around duckdb import (database.py top) — acceptable for optional dependency but should log explicitly the missing dependency and document test behavior.

## Remediations
- Add a simple migration/versioning table (schema_version) to track schema changes and apply migrations deterministically.
- Add tests that exercise both duckdb-backed and JSON-fallback database paths. Evidence: database.py contains JSON fallback logic (lines ~1-80).

## Evidence pointers
- database.py: DDL strings and sequences (file: database.py lines ~1-300 and further). See create table blocks for motions, mp_votes, embeddings, fused_embeddings.