fix: Do not save null values for TEAV [DHIS2-21599] (2.42)

[enricocolasante]

Summary

Backport of DHIS2-21599 ("Do not save null values for TEAV", #24302) to the 2.42 branch.
As of this change, the tracker importer no longer persists tracked entity attribute values that
have no value. Unlike the master version, this backport does not ship a database migration to
clean up pre-existing null/empty attribute values; instead it adds a data integrity check that
surfaces those rows to administrators so they can be resolved manually. This keeps the stable 2.42
line free of automatic, irreversible data changes on upgrade.

Changes

• Tracker import (AbstractTrackerPersister.java): no longer writes a tracked entity attribute
  value when the imported value is empty. An empty value for an existing attribute is treated as a
  delete; an empty value for an attribute not yet in the database is a no-op. The deleted entry is
  intentionally kept in the in-memory map so later occurrences of the same TE + attribute within the
  same import run still see it as existing (the DELETE is not flushed until the end of the run).

• Data integrity check instead of a migration: adds
  data-integrity-checks/programs/tracked_entity_attribute_null_value.yaml and registers it in
  data-integrity-checks.yaml. The check flags any trackedentityattributevalue row whose value
  column is null or empty, distinguishing two cases:

  • rows that have an encryptedvalue but no plain text value (previously confidential
    attributes), and
  • rows that have neither a plain text nor an encrypted value.

  It is marked SEVERE / is_slow and its recommendation explains, per case, how to either recover
  the plain text or delete the affected rows — mirroring the 2.44 migration notes, but leaving the
  action in the administrator's hands rather than performing it automatically.

• Tests:

  • DataIntegrityTrackedEntityAttributeNullValueControllerTest — new controller integration test
    covering the no-data, plain-value-present, empty-only, and encrypted-only cases. Anomalous rows
    are inserted via raw SQL because the service layer refuses to persist a null value.
  • TrackedEntityAttributeTest — adds import-level coverage, notably
    shouldNotPersistAttributeValueWhenImportingEmptyValueForAttributeNotInDb and
    shouldDeleteAttributeValueWhenImportingEmptyValueForExistingAttribute.

• Housekeeping: bumps section_order of single_events_null_occurred_date.yaml from 3 to 6 to
  make room for the new check ordering in the Programs section.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud