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Example 05: Subgraph Pattern Matching

Use SPARQL patterns to validate system topology and structure.

What You'll Learn

  • ✅ Define SPARQL validation patterns
  • ✅ Check system structure
  • ✅ Validate relationships
  • ✅ Advanced structural validation

Overview

Pattern matching validates system topology using SPARQL:

graph LR
    A[Define Pattern] --> B[SPARQL Query]
    C[Brick Model] --> B
    B --> D{Pattern Match?}
    D -->|Yes| E[✓ Valid Structure]
    D -->|No| F[✗ Structural Issue]

    style A fill:#fff9c4
    style C fill:#e3f2fd
    style E fill:#c8e6c9
    style F fill:#ffcdd2

Example Pattern

Validate boiler has supply and return sensors:

from hhw_brick.validation import SubgraphPatternValidator

validator = SubgraphPatternValidator()

# Define pattern
pattern = """
SELECT ?boiler ?supply ?return WHERE {
    ?boiler a brick:Boiler .
    ?boiler brick:hasPoint ?supply .
    ?boiler brick:hasPoint ?return .
    ?supply a brick:Hot_Water_Supply_Temperature_Sensor .
    ?return a brick:Hot_Water_Return_Temperature_Sensor .
}
"""

# Validate
result = validator.validate_pattern(
    ttl_file_path="building_105.ttl",
    pattern_query=pattern,
    min_matches=1
)

if result['valid']:
    print(f"✓ Pattern matched! Found {result['match_count']} instances")

Run Example

python examples/05_subgraph_pattern_matching.py

Next Steps

📂 Source Code: examples/05_subgraph_pattern_matching.py