# DuckDB Results Structure Fix - Summary

## Issue Overview

The issue was related to how DuckDB query results were being stored and accessed in templates. The results were being stored as raw lists of tuples (double arrays), making it difficult to access the data in templates. This was causing template rendering errors like:

```
Template rendering error: 'dict object' has no attribute 'data', template: {{ extract_repo_metrics.data.command_1 }}
```

## Work Completed

### 1. Root Cause Analysis

We identified that the root cause of the issue was in the `execute_duckdb_task` function in `action.py`. The function was storing the raw `fetchall()` results directly, resulting in a double array structure. In contrast, the `execute_postgres_task` function was processing the results into a more structured format with "rows", "row_count", and "columns" keys.

### 2. Code Changes

We modified the `execute_duckdb_task` function in `action.py` to process query results similar to how `execute_postgres_task` does it. The key changes include:

- Getting the cursor object from `duckdb_con.execute(cmd)`
- Getting the column names from `cursor.description`
- Converting each row tuple into a dictionary with column names as keys
- Storing the processed results in a structured format with "rows", "row_count", and "columns" keys for SELECT queries
- Storing a simpler result structure for non-SELECT queries

### 3. Template Reference Updates

We updated the template references in the GitHub metrics example YAML file to access the "rows" key for DuckDB task results:

```yaml
repo_data: "{{ extract_repo_metrics.result.command_1.rows }}"
stats_data: "{{ extract_repo_metrics.result.command_3.rows }}"
```

This ensures that the templates are accessing the rows of data rather than the entire result object.

### 4. Documentation

We created two documentation files:

1. **duckdb_results_fix.md**: Explains the issue, root cause, changes made, and guidance on how to access database query results in templates.
2. **duckdb_results_test_plan.md**: Provides a comprehensive test plan for verifying the changes.

## Current Status

The changes have been implemented and are ready for testing. The test plan provides a structured approach to verify that the changes resolve the double array issue and don't introduce any regressions.

## Expected Impact

These changes should resolve the template rendering errors related to accessing DuckDB query results. The workflow should now execute without any errors, and templates should be able to access DuckDB query results in a consistent way, similar to how they access Postgres query results.

## Future Considerations

In the future, we may want to consider:

1. Standardizing the result structure for all task types to make it more consistent and easier to access in templates.
2. Adding more robust error handling for template rendering errors to provide more helpful error messages.
3. Providing helper functions or macros to simplify accessing complex data structures in templates.

## Related Files

- `/noetl/action.py`: Modified to process DuckDB query results into a more accessible format
- `/examples/github/github_metrics_example.yaml`: Updated to access the "rows" key for DuckDB task results
- `/docs/duckdb_results_fix.md`: Documentation explaining the issue and changes made
- `/docs/duckdb_results_test_plan.md`: Test plan for verifying the changes