updated series_index to float and added UniqueConstraint to audiobook and audiobook_author

python/orm/richie/audiobook.py

@@ -12,6 +12,7 @@ class AudiobookAuthor(TableBase):
     """Canonical audiobook author."""
 
     __tablename__ = "audiobook_author"
+    __table_args__ = (UniqueConstraint("name"),)
 
     name: Mapped[str] = mapped_column(String, unique=True)
 
@@ -36,11 +37,19 @@ class Audiobook(TableBase):
     """Canonical audiobook title."""
 
     __tablename__ = "audiobook"
+    __table_args__ = (
+        UniqueConstraint(
+            "author_id",
+            "series_id",
+            "title",
+            postgresql_nulls_not_distinct=True,
+        ),
+    )
 
     title: Mapped[str] = mapped_column(String)
     author_id: Mapped[int] = mapped_column(ForeignKey("main.audiobook_author.id", ondelete="CASCADE"))
     series_id: Mapped[int | None] = mapped_column(ForeignKey("main.audiobook_series.id", ondelete="SET NULL"))
-    series_index: Mapped[int] = mapped_column(default=0)
+    series_index: Mapped[float] = mapped_column(default=0.0)
 
     author: Mapped[AudiobookAuthor] = relationship("AudiobookAuthor", back_populates="books")
     series: Mapped[AudiobookSeries | None] = relationship("AudiobookSeries", back_populates="books")