# Neo4j Diagnostic Queries

## Issue: No relationships found in Neo4j

If you're seeing "(no changes, no records)" when querying for `CAUSES` relationships, here are diagnostic queries to check what's actually in the database.

## Diagnostic Queries

### 1. Check if any nodes exist
```cypher
MATCH (n)
RETURN count(n) as node_count
LIMIT 1
```

### 2. Check if Concept nodes exist
```cypher
MATCH (n:Concept)
RETURN count(n) as concept_count, 
       collect(DISTINCT labels(n)) as labels,
       collect(DISTINCT keys(n)) as properties
LIMIT 10
```

### 3. Check all relationship types
```cypher
CALL db.relationshipTypes() YIELD relationshipType
RETURN relationshipType
```

### 4. Check all node labels
```cypher
CALL db.labels() YIELD label
RETURN label
```

### 5. Check all relationships (any type)
```cypher
MATCH (n)-[r]->(m)
RETURN type(r) as relationship_type, 
       count(r) as count,
       labels(n) as from_labels,
       labels(m) as to_labels
LIMIT 50
```

### 6. Check for CAUSES relationships specifically
```cypher
MATCH (n)-[r:CAUSES]->(m)
RETURN n, r, m
LIMIT 50
```

### 7. Check for relationships with lowercase "causes"
```cypher
MATCH (n)-[r]->(m)
WHERE type(r) =~ '(?i)causes'
RETURN type(r) as relationship_type, n, r, m
LIMIT 50
```

### 8. Check all nodes and their relationships
```cypher
MATCH (n)
OPTIONAL MATCH (n)-[r]->(m)
RETURN n, labels(n) as node_labels, 
       type(r) as relationship_type, 
       m, labels(m) as target_labels
LIMIT 50
```

### 9. Check for nodes created by the service (by job_id property)
```cypher
MATCH (n)-[r]->(m)
WHERE r.job_id IS NOT NULL
RETURN n, r, m, r.job_id as job_id
LIMIT 50
```

### 10. Check database statistics
```cypher
MATCH (n)
RETURN count(n) as total_nodes,
       size([(n)-[r]->() | r]) as total_relationships
```

## Common Issues and Solutions

### Issue 1: No nodes at all
**Symptom**: Query 1 returns 0 nodes
**Cause**: Service hasn't written anything to Neo4j, or connection failed
**Solution**: 
- Check service logs: `docker-compose logs multi-document-upload-service`
- Verify Neo4j connection in service configuration
- Check if job completed with 0 relations (extraction failed)

### Issue 2: Nodes exist but no relationships
**Symptom**: Query 1 returns nodes, but Query 6 returns no relationships
**Cause**: Relationships weren't created, or different relationship type
**Solution**:
- Check Query 5 to see what relationship types actually exist
- Check service logs for graph writing errors
- Verify the job actually extracted relations (check job status)

### Issue 3: Different relationship type
**Symptom**: Query 5 shows relationships but not `CAUSES`
**Cause**: Service might be using a different relationship type
**Solution**:
- Check Query 3 to see all relationship types
- Update query to use the correct relationship type

### Issue 4: Different node labels
**Symptom**: Query 6 returns no results, but Query 2 shows different labels
**Cause**: Service might be using different node labels
**Solution**:
- Check Query 2 to see what labels exist
- Update query to match actual labels

## Expected Structure

After a successful upload, you should see:

### Nodes
- **Label**: `Concept`
- **Properties**: `name`, `lastSeen`

### Relationships
- **Type**: `CAUSES`
- **Properties**: `confidence`, `explanation`, `source_file_id`, `source_snippet`, `job_id`, `model`, `updated_at`

### Example Query
```cypher
MATCH (cause:Concept)-[r:CAUSES]->(effect:Concept)
RETURN cause.name as cause, 
       effect.name as effect, 
       r.confidence as confidence,
       r.job_id as job_id,
       r.source_file_id as source_file
LIMIT 50
```

## Troubleshooting Steps

1. **Check service logs**:
   ```bash
   docker-compose logs -f multi-document-upload-service
   ```

2. **Check if job completed successfully**:
   ```bash
   curl http://localhost:8000/api/multi-docs/jobs/{job_id}
   ```

3. **Check Neo4j connection**:
   ```bash
   docker-compose logs neo4j | grep -i error
   ```

4. **Verify Neo4j is running**:
   ```bash
   docker-compose ps neo4j
   ```

5. **Test Neo4j connection manually**:
   ```bash
   docker-compose exec neo4j cypher-shell -u neo4j -p password "MATCH (n) RETURN count(n)"
   ```

## Next Steps

1. Run the diagnostic queries above
2. Check the service logs for errors
3. Verify the job status via API
4. Re-upload documents after fixing dependencies
5. Check if relations were actually extracted (job status should show relation count)