Add Planet model

models/planet.py

@@ -0,0 +1,19 @@
+from sqlalchemy import Column, String, Integer, ForeignKey
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.api.db.base_class import Base
+import uuid
+
+class Planet(Base):
+    __tablename__ = "planets"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String, unique=True, nullable=False)
+    description = Column(String, nullable=True)
+    diameter = Column(Integer, nullable=False)
+    mass = Column(Integer, nullable=False)
+    distance_from_sun = Column(Integer, nullable=False)
+
+    # Timestamps
+    created_at = Column(Integer, default=func.now())
+    updated_at = Column(Integer, default=func.now(), onupdate=func.now())