Deleting an Entity

Deleting data is a fundamental operation in any database system. This tutorial demonstrates how to delete a single entity using Onyx Database.

Steps to Delete an Entity (Onyx Cloud Database)

1

Save an Entity

Create and save an entity that you will later delete.
1val person = Person(
2    firstName = "John",
3    lastName = "Elway",
4    dateCreated = Date()
5)
6
7val savedPerson = this.save(person)
8println("Person ${savedPerson.id} saved successfully")
2

Delete the Entity

Use the Persistence Manager's delete method to remove the entity.
1this.delete(savedPerson)
3

Verify the Deletion

Attempt to retrieve the deleted entity to confirm it no longer exists.
1val deletedPerson = this.findById<Person>(savedPerson.id)
2if (deletedPerson == null) {
3    println("Entity was deleted successfully")
4}
If the entity is not found, the deletion was successful. Otherwise, verify the identifier and ensure no exceptions were thrown during the delete operation.

Important Notes

  • The delete operation is an atomic operation. Ensure that the entity's primary key is correctly configured.
  • Onyx Database does not differentiate between soft deletes and hard deletes. Use an appropriate deletion strategy based on your requirements.

Troubleshooting

  • Entity Not Found: Verify that the correct identifier was provided for the entity being deleted.
  • Deletion Failed: Ensure the entity exists and the Persistence Manager is properly initialized.
  • Unexpected Exceptions: Check the logs for error details, such as database connection issues or constraint violations.

Next Steps

Once you have mastered deleting entities, explore related topics: