Added models for database schema

src/backend/lib/models.py

@@ -0,0 +1,41 @@
+from typing import Optional
+from typing_extensions import Annotated
+from sqlalchemy import func, DateTime, ForeignKey
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+import datetime
+
+timestamp = Annotated[
+    datetime.datetime,
+    mapped_column(nullable=False, server_default=func.CURRENT_TIMESTAMP())
+]
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+class Book(Base):
+    __tablename__ = "books"
+
+    book_id: Mapped[int] = mapped_column(primary_key=True, nullable=False)
+    title: Mapped[str]
+    author: Mapped[Optional[str]]
+    categories: Mapped[Optional[str]]
+    cover: Mapped[Optional[bytes]]
+    pages: Mapped[Optional[int]]
+    progress: Mapped[Optional[float]]
+    file_name: Mapped[str]
+    description: Mapped[Optional[str]]
+    date: Mapped[timestamp]
+    rights: Mapped[Optional[str]]
+    tags: Mapped[Optional[str]]
+    identifier: Mapped[Optional[str]]
+    publisher: Mapped[Optional[str]]
+
+
+class Collection(Base):
+    __tablename__ = "collections"
+
+    collection: Mapped[str]
+    book_id: Mapped[int] = mapped_column(ForeignKey(Book.book_id))
+    collection_id: Mapped[int] = mapped_column(primary_key=True)