add review

app/models/review.py

@@ -0,0 +1,36 @@
+from .db import db
+
+
+class Review(db.Model):
+    __tablename__ = 'reviews'
+
+    id = db.Column(db.Integer, primary_key=True)
+    user_id = db.Column(
+        db.Integer, db.ForeignKey('users.id'), nullable=False)
+    product_id = db.Column(
+        db.Integer, db.ForeignKey('products.id'), nullable=False)
+    content = db.Column(db.String(1000), nullable=False)
+    stars = db.Column(db.Integer, nullable=False)
+    created_at = db.Column(db.DateTime(timezone=True),
+                           nullable=False, server_default=db.func.now())
+    updated_at = db.Column(db.DateTime(timezone=True))
+
+    user = db.relationship(
+        'User', back_populates='reviews', foreign_keys=[user_id])
+    product = db.relationship(
+        'Product', back_populates='reviews', foreign_keys=[product_id])
+
+    def to_dict(self):
+        return {
+            'id': self.id,
+            'user_id': self.user_id,
+            'product_id': self.product_id,
+            'content': self.content,
+            'stars': self.stars,
+            'created_at': self.created_at
+        }
+
+    def to_dict_stars(self):
+        return {
+            'stars' : int(self.stars)
+        }