Deleting Objects#

Serverless ADR provides robust APIs for deleting report-related objects, including Items, Templates, Sessions, and Datasets. These operations allow you to remove outdated or unnecessary data from your reporting system efficiently.

Deletion Methods#

  1. Deleting Individual Objects

Every model instance exposes a .delete() method that permanently removes that object from the database.

Example:

from ansys.dynamicreporting.core.serverless import Item

item = Item.get(name="intro_text")
item.delete()

  1. Delete Multiple Objects via Query

Query sets (ObjectSet) returned by filter(), find(), or ADR’s query() method support a bulk .delete() method that deletes all objects in the set.

items_to_delete = adr.query(Item, query="A|i_tags|cont|old_project;")
count_deleted = items_to_delete.delete()
print(f"Deleted {count_deleted} items.")

Example Usage Patterns#

Deleting a Single Session:

session = Session.get(guid="4ee905f0-f611-11e6-8901-ae3af682bb6a")
session.delete()

Deleting Multiple Datasets by Tag:

old_datasets = Dataset.filter(tags__contains="deprecated")
deleted_count = old_datasets.delete()
print(f"Deleted {deleted_count} datasets.")

Deleting Sessions by Tag

from ansys.dynamicreporting.core.serverless import Session

old_sessions = Session.filter(tags__contains="deprecated")
count = old_sessions.delete()
print(f"Deleted {count} sessions.")

Deleting Datasets with Specific Filename Patterns

from ansys.dynamicreporting.core.serverless import Dataset

datasets_to_remove = Dataset.filter(filename="test_data")
deleted = datasets_to_remove.delete()
print(f"Deleted {deleted} datasets.")

Deleting Templates by Name

from ansys.dynamicreporting.core.serverless import Template

templates = Template.filter(name="Old Layout")
deleted = templates.delete()
print(f"Deleted {deleted} templates.")

Important Notes and Caveats#

  • Automatic Cascading: Deleting a Template automatically deletes its child templates but not the associated Items. Similarly, deleting a Session or Dataset will delete dependent Items.

  • Permanent Action: Deletions are irreversible through the API. Always ensure that critical data is backed up before deletion.

  • Permissions: Ensure you have proper database access permissions to perform deletion operations.

  • Query Precision: Use precise query filters to prevent accidental mass deletions.

Error Handling#

  • DoesNotExist Exception: Raised when .delete() is called on an object that no longer exists in the database.

  • Database Integrity Errors: If database constraints prevent deletion (e.g., foreign key constraints), exceptions will be raised. Handle these to avoid partial deletions.

  • Invalid Query Filters: Malformed or unsupported query filters will raise an ADRException during query or delete calls.

Best Practices#

  • Preview Objects Before Deletion: Always iterate over query results or inspect objects before deleting to confirm correctness.

  • Backup Important Data: Before bulk deletes, create database backups or export data.

  • Use Soft Deletes If Needed: If deletion safety is a concern, consider implementing a “soft delete” flag in your application logic.

  • Clean-Up Orphaned Data: After deletion, ensure no orphaned references remain that could cause errors.