Update database architecture. Add genres and actors

database/models/game_genres.py

@@ -0,0 +1,24 @@
+from sqlalchemy import Column, Integer, ForeignKey, PrimaryKeyConstraint, String
+from sqlalchemy.orm import relationship
+
+from ..database import Base
+
+
+class GameGenre(Base):
+    __tablename__ = "game_genres"
+
+    id = Column(Integer, primary_key=True)
+    genre = Column(String, nullable=False, unique=True)
+
+    games = relationship("Game", secondary="game_to_genre",
+                         lazy="selectin")
+
+
+class GameToGenre(Base):
+    __tablename__ = "game_to_genre"
+    __table_args__ = (
+        PrimaryKeyConstraint("game_id", "genre_id"),
+    )
+
+    game_id = Column(Integer, ForeignKey("games.id"), nullable=False)
+    genre_id = Column(Integer, ForeignKey("game_genres.id"), nullable=False)