mgt c4

backend/app/models.py

@@ -0,0 +1,27 @@
+from datetime import datetime, timezone
+from typing import Optional
+import sqlalchemy as sa
+import sqlalchemy.orm as so
+from app import db
+
+class User(db.Model):
+    id: so.Mapped[int] = so.mapped_column(primary_key=True)
+    username: so.Mapped[str] = so.mapped_column(sa.String(64), index=True, unique=True)
+    email: so.Mapped[str] = so.mapped_column(sa.String(120), index=True, unique=True)
+    password_hash: so.Mapped[Optional[str]] = so.mapped_column(sa.String(256))
+    posts: so.WriteOnlyMapped['Post'] = so.relationship(back_populates='author')
+
+    def __repr__(self):
+        return '<User {}>'.format(self.username)
+
+class Post(db.Model):
+    id: so.Mapped[int] = so.mapped_column(primary_key=True)
+    body: so.Mapped[str] = so.mapped_column(sa.String(140))
+    timestamp: so.Mapped[datetime] = so.mapped_column(index=True, default=lambda: datetime.now(timezone.utc))
+    user_id: so.Mapped[int] = so.mapped_column(sa.ForeignKey(User.id), index=True)
+    author: so.Mapped[User] = so.relationship(back_populates='posts')
+
+    def __repr__(self):
+        return '<Post {}>'.format(self.body)
+
+