Cache last sign in date in User table

server/mergin/auth/models.py

@@ -36,6 +36,8 @@ class User(db.Model):
         default=datetime.datetime.utcnow,
     )
 
+    last_signed_in = db.Column(db.DateTime(), nullable=True)
+
     __table_args__ = (
         db.Index("ix_user_username", func.lower(username), unique=True),
         db.Index("ix_user_email", func.lower(email), unique=True),
@@ -289,6 +291,7 @@ def __init__(self, user_id: int, ua: str, ip: str, device_id: Optional[str] = No
         self.user_agent = ua
         self.ip_address = ip
         self.device_id = device_id
+        self.timestamp = datetime.datetime.now(tz=datetime.timezone.utc)
 
     @staticmethod
     def add_record(user_id: int, req: request) -> None:
@@ -300,4 +303,37 @@ def add_record(user_id: int, req: request) -> None:
             return
         lh = LoginHistory(user_id, ua, ip, device_id)
         db.session.add(lh)
+
+        # cache user last login
+        User.query.filter_by(id=user_id).update({"last_signed_in": lh.timestamp})
+        db.session.commit()
+
+    @staticmethod
+    def get_users_last_signed_in(user_ids: list) -> dict:
+        """Get users last signed in dates.
+        Result is also cached in User table for future use.
+        """
+        result = (
+            db.session.query(
+                LoginHistory.user_id,
+                func.max(LoginHistory.timestamp).label("last_signed_in"),
+            )
+            .filter(LoginHistory.user_id.in_(user_ids))
+            .group_by(LoginHistory.user_id)
+            .all()
+        )
+
+        user_mapping = [
+            {
+                "id": row.user_id,  # user_id as PK in User table
+                "last_signed_in": row.last_signed_in,
+            }
+            for row in result
+        ]
+        if not user_mapping:
+            return {}
+
+        # cache users last signed in
+        db.session.bulk_update_mappings(User, user_mapping)
         db.session.commit()
+        return {item["id"]: item["last_signed_in"] for item in user_mapping}

server/mergin/tests/test_auth.py

@@ -77,6 +77,15 @@ def test_login(client, data, headers, expected):
         )
         assert login_history
         assert login_history.device_id == str(headers.get("X-Device-Id"))
+        assert user.last_signed_in == login_history.timestamp
+        users_last_signed_in = LoginHistory.get_users_last_signed_in([user.id])
+        assert users_last_signed_in[user.id] == login_history.timestamp
+
+        # verify missing value is cached on first LoginHistory access
+        user.last_signed_in = None
+        db.session.commit()
+        users_last_signed_in = LoginHistory.get_users_last_signed_in([user.id])
+        assert user.last_signed_in == users_last_signed_in[user.id]
 
 
 def test_logout(client):
@@ -376,6 +385,7 @@ def test_api_login(client, data, headers, expected):
             .first()
         )
         assert login_history
+        assert user.last_signed_in == login_history.timestamp
 
 
 def test_api_login_from_urllib(client):
@@ -394,6 +404,8 @@ def test_api_login_from_urllib(client):
             .first()
         )
         assert not login_history
+        # we do not have recored last login yet
+        assert user.last_signed_in is None
 
 
 def test_api_user_profile(client):

server/migrations/community/b9ec9ab6694f_add_user_last_signed_in.py

@@ -0,0 +1,25 @@
+"""Add user last signed in
+
+Revision ID: b9ec9ab6694f
+Revises: 6cb54659c1de
+Create Date: 2025-09-09 15:43:19.554498
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = "b9ec9ab6694f"
+down_revision = "6cb54659c1de"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.add_column("user", sa.Column("last_signed_in", sa.DateTime(), nullable=True))
+
+
+def downgrade():
+    op.drop_column("user", "last_signed_in")