Add migration to extend distribution content_url to LONG

alembic/README.md

@@ -17,7 +17,7 @@ With the sqlserver container running, you can migrate to the latest schema with:
 ```commandline
 docker run -v $(pwd)/alembic:/alembic:ro  -v $(pwd)/src:/app -it --network aiod_default  aiod-migration
 ```
-Make sure that the specifid `--network` is the docker network that has the `sqlserver` container.
+Make sure that the specified `--network` is the docker network that has the `sqlserver` container.
 The alembic directory is mounted to ensure the latest migrations are available, 
 the src directory is mounted so the migration scripts can use defined classes and variable from the project.
 
@@ -28,5 +28,21 @@ the src directory is mounted so the migration scripts can use defined classes an
 Following the usage commands above, on a new release we should run alembic to ensure the latest schema changes are applied.
 The default entrypoint of the container specifies to upgrade the database to the latest schema.
 
+## Adding a Revision
+
+Build the docker image above, and start a container of it with shell as entry: 
+
+```bash
+docker run -v $(pwd)/alembic:/alembic  -v $(pwd)/src:/app -it --network aiod_default --entrypoint=/bin/bash  aiod-migration
+```
+
+Then follow regular `alembic` steps:
+```bash
+alembic revision -m "revision message"
+```
+Then edit the generated file (note that it should also exist on your host machine, so you might prefer to edit it there).
+
+Note that working from a docker container is not strictly necessary, but it helps set up the PYTHONPATH correctly, so that you can import from the `src` directory.
+
 ## TODO
  - set up support for auto-generating migration scripts: https://alembic.sqlalchemy.org/en/latest/autogenerate.html

alembic/alembic/versions/279e17c48ea1_extend_description_length.py

@@ -0,0 +1,42 @@
+"""Extend description length
+
+Revision ID: 279e17c48ea1
+Revises: 0a23b40cc09c
+Create Date: 2024-10-29 14:38:30.684251
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+from sqlalchemy import String
+
+from database.model.field_length import LONG
+
+# revision identifiers, used by Alembic.
+revision: str = "279e17c48ea1"
+down_revision: Union[str, None] = "0a23b40cc09c"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # All models that have associated distributions
+    for table in [
+        "dataset",
+        "case_study",
+        "publication",
+        "computational_asset",
+        "ml_model",
+        "experiment",
+    ]:
+        op.alter_column(
+            f"distribution_{table}",
+            "content_url",
+            type_=String(LONG),
+        )
+
+
+def downgrade() -> None:
+    # from NORMAL
+    pass