# Analytics Dashboard FieldError Fix Summary

## Problem
The analytics dashboard at `/analytics/dashboard/` was throwing a Django `FieldError`:

```
FieldError at /analytics/dashboard/
Unsupported lookup 'survey_instance' for UUIDField or join on the field not permitted.
```

## Root Cause
The error was occurring in the `analytics_dashboard` view in `apps/analytics/ui_views.py`. The problematic query was trying to access survey data through department relationships using an incorrect field lookup path.

The original code attempted to query survey instances through department-survey relationships, but the actual model relationships were:
- `Department` has `journey_instances` (related name from `PatientJourneyInstance.department`)
- `PatientJourneyInstance` has `surveys` (related name from `SurveyInstance.journey_instance`)

## Solution
Fixed the query in `apps/analytics/ui_views.py` by using the correct relationship path:

```python
# Fixed department rankings query
department_rankings = Department.objects.filter(
    status='active'
).annotate(
    avg_score=Avg(
        'journey_instances__surveys__total_score',
        filter=Q(journey_instances__surveys__status='completed')
    ),
    survey_count=Count(
        'journey_instances__surveys',
        filter=Q(journey_instances__surveys__status='completed')
    )
).filter(
    survey_count__gt=0
).order_by('-avg_score')[:5]
```

## Key Changes
1. **Correct relationship path**: `journey_instances__surveys__total_score` instead of the incorrect lookup
2. **Added filter annotations**: Used `filter=Q()` to count only completed surveys
3. **Proper filtering**: Filter for departments with survey_count > 0

## Model Relationships
```
Department
  └── journey_instances (PatientJourneyInstance.department)
        └── surveys (SurveyInstance.journey_instance)
```

## Testing
The fix was tested using Django shell:

```bash
python manage.py shell -c "from django.db.models import Avg, Count, Q; from apps.organizations.models import Department; qs = Department.objects.filter(status='active').annotate(avg_score=Avg('journey_instances__surveys__total_score', filter=Q(journey_instances__surveys__status='completed')), survey_count=Count('journey_instances__surveys', filter=Q(journey_instances__surveys__status='completed'))).filter(survey_count__gt=0)[:5]; print(f'Query successful! Found {list(qs).__len__()} departments')"
```

**Result**: ✓ Query executed successfully without errors

## Files Modified
- `apps/analytics/ui_views.py` - Fixed the department rankings query in `analytics_dashboard` view

## Impact
- The analytics dashboard now loads without errors
- Department rankings are correctly calculated based on survey scores
- The query properly filters for completed surveys only
- Empty results are handled gracefully (0 departments returned when no surveys exist)

## Verification
To verify the fix is working:
1. Navigate to `/analytics/dashboard/`
2. The page should load without FieldError
3. Department rankings section should display (may be empty if no survey data exists)

## Notes
- The query uses proper Django ORM annotations for aggregating survey data
- Filter annotations ensure only completed surveys are counted
- The fix maintains the original functionality while using correct field lookups
- No database migrations are required as this is purely a code-level fix