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Querying a Hyrbid Property Graph

You can use Cypher Queries or the NeoModel ORM to query the property graph. The NeoModel ORM Schema is defined in hpg_neo4j/orm.py. You should place and run your queries in analyses/<ANALYSIS_NAME>. For further details, see the example query files provided: example.orm.py and example.py in the analyses/example folder.

$ python3 -m analyses.example.example
$ python3 -m analyses.example.exampleorm

Querying with ORM

The Neomodel ORM schema is defined in hpg_neo4j/orm.py. You can query the property graph using the ORM by just importing the hpg_neo4j.orm package. By default, the ORM will connect to the active neo4j database.

import hpg_neo4j.orm as ORM
import neomodel

# get the first identifier and print its name/value 
identifier = ORM.ASTNode.nodes.first_or_none(Type='Identifier')
print('The first identifier is {0}'.format(identifier.Code)

For more information on how to use the ORM, please refer to the Neomodel documentation

Querying with Cypher

To query the hpgs, you can use the hpg_neo4j.db_utility module.

# import the querying module
import hpg_neo4j.db_utility as neo4jDatabaseUtilityModule

# define a query
def get_query():
   query="""
   YOUR CYPHER QUERY GOES HERE
   """
   return query

# run the query 
def run_query(tx):
   query = get_query()
   return tx.run(query)

# execute the run_query() function within a neo4j transaction context
results = neo4jDatabaseUtilityModule.exec_fn_within_transaction(run_query)

Example Queries

Example 1. Finding identifiers that contain the keyword example in their name

query = """
	MATCH (n {Type: 'Identifier'})
	WHERE (n.Code =~ 'example')
	RETURN n
"""

Example 2. Finding all AST children of a node with a given id, say 2.

query = """
        MATCH (root { Id: '2' })-[:AST_parentOf]->(child)
        RETURN collect(distinct child)
        AS children
"""

Example 3. Finding all print()statements

query = """
	MATCH (t {Type: 'ExpressionStatement'})-[:AST_parentOf {RelationType: 'expression'}]->(n {Type: 'CallExpression'})-[:AST_parentOf {RelationType: 'callee'}]-> (pr {Type: 'Identifier', Code: 'print'}), 
	RETURN t, pr
"""

Example 4. Finding all HTTP requests with the Fetch API.

query = """
	MATCH (t {Type: 'ExpressionStatement'})-[:AST_parentOf {RelationType: 'expression'}]->(n {Type: 'CallExpression'})-[:AST_parentOf {RelationType: 'callee'}]-> (req {Type: 'Identifier', Code: 'fetch'}), 
	(n)-[:AST_parentOf {RelationType: 'arguments', Arguments: '{\"arg\":0}'}]->(a)
	RETURN t, n, a
"""

Example 5. Finding the PDG relations of a given node id, say 2, for a given a variable name, say XYZ

query = """
        MATCH (n_s { Id: '2' })<-[:PDG_parentOf { Arguments: 'XYZ' }]-(n_t)
        RETURN collect(distinct n_t) 
        AS resultset
"""