From f62af090a44f95a44681abe2bd17aee8e98b8639 Mon Sep 17 00:00:00 2001
From: PGijsbers <p.gijsbers@tue.nl>
Date: Wed, 6 May 2026 10:31:11 +0200
Subject: [PATCH 1/2] Move knowledge of how data status works to db layer

---
 src/database/datasets.py       | 19 +++++++++++--------
 src/routers/openml/datasets.py | 12 +++++-------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/database/datasets.py b/src/database/datasets.py
index d6f91706..ba0edcad 100644
--- a/src/database/datasets.py
+++ b/src/database/datasets.py
@@ -14,7 +14,7 @@
     DuplicatePrimaryKeyError,
     ForeignKeyConstraintError,
 )
-from schemas.datasets.openml import Feature
+from schemas.datasets.openml import DatasetStatus, Feature
 
 
 async def get(id_: int, connection: AsyncConnection) -> Row | None:
@@ -105,18 +105,21 @@ async def get_description(
 
 async def get_status(id_: int, connection: AsyncConnection) -> Row | None:
     """Get most recent status for the dataset."""
-    row = await connection.execute(
-        text(
-            """
+    row = (
+        await connection.execute(
+            text(
+                """
     SELECT *
     FROM dataset_status
     WHERE did = :dataset_id
     ORDER BY status_date DESC
+    LIMIT 1
     """,
-        ),
-        parameters={"dataset_id": id_},
-    )
-    return row.first()
+            ),
+            parameters={"dataset_id": id_},
+        )
+    ).first()
+    return DatasetStatus(row.status) if row else DatasetStatus.IN_PREPARATION
 
 
 async def get_latest_processing_update(dataset_id: int, connection: AsyncConnection) -> Row | None:
diff --git a/src/routers/openml/datasets.py b/src/routers/openml/datasets.py
index 68d86aed..e14fa804 100644
--- a/src/routers/openml/datasets.py
+++ b/src/routers/openml/datasets.py
@@ -366,7 +366,7 @@ async def update_dataset_status(
         raise DatasetAdminOnlyError(msg)
 
     current_status = await database.datasets.get_status(dataset_id, expdb)
-    if current_status and current_status.status == status:
+    if current_status == status:
         msg = f"Illegal status transition, requested status {status} matches current status."
         raise DatasetStatusTransitionError(msg)
 
@@ -376,14 +376,14 @@ async def update_dataset_status(
     #  - in preparation => deactivated  (add a row)
     #  - active => deactivated  (add a row)
     #  - deactivated => active  (delete a row)
-    if current_status is None or status == DatasetStatus.DEACTIVATED:
+    if current_status == DatasetStatus.IN_PREPARATION or status == DatasetStatus.DEACTIVATED:
         await database.datasets.update_status(
             dataset_id,
             status,
             user_id=user.user_id,
             connection=expdb,
         )
-    elif current_status.status == DatasetStatus.DEACTIVATED:
+    elif current_status == DatasetStatus.DEACTIVATED:
         await database.datasets.remove_deactivated_status(dataset_id, expdb)
     else:
         msg = f"Unknown status transition: {current_status} -> {status}"
@@ -392,7 +392,7 @@ async def update_dataset_status(
     logger.info(
         "Dataset {dataset_id} changed from {previous} to {current}",
         dataset_id=dataset_id,
-        previous=current_status.status if current_status else DatasetStatus.IN_PREPARATION,
+        previous=current_status,
         current=status,
     )
     return {"dataset_id": dataset_id, "status": status}
@@ -427,8 +427,6 @@ async def get_dataset(
         database.datasets.get_status(dataset_id, expdb_db),
     )
 
-    status_ = DatasetStatus(status.status) if status else DatasetStatus.IN_PREPARATION
-
     description_ = ""
     if description:
         description_ = description.description.replace("\r", "").strip()
@@ -446,7 +444,7 @@ async def get_dataset(
     return DatasetMetadata(
         id=dataset.did,
         visibility=dataset.visibility,
-        status=status_,
+        status=status,
         name=dataset.name,
         licence=dataset.licence,
         version=dataset.version,

From 0971055911c23560d75b0f78031e7f63ca733248 Mon Sep 17 00:00:00 2001
From: PGijsbers <p.gijsbers@tue.nl>
Date: Wed, 6 May 2026 11:03:27 +0200
Subject: [PATCH 2/2] fix minor oversights

---
 src/database/datasets.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/database/datasets.py b/src/database/datasets.py
index ba0edcad..9abfc14c 100644
--- a/src/database/datasets.py
+++ b/src/database/datasets.py
@@ -103,13 +103,13 @@ async def get_description(
     return row.first()
 
 
-async def get_status(id_: int, connection: AsyncConnection) -> Row | None:
+async def get_status(id_: int, connection: AsyncConnection) -> DatasetStatus:
     """Get most recent status for the dataset."""
     row = (
         await connection.execute(
             text(
                 """
-    SELECT *
+    SELECT status
     FROM dataset_status
     WHERE did = :dataset_id
     ORDER BY status_date DESC