def test_create_undirected_relationship():
rel = Relationship('KNOWS',
Node('User', var='m'),
Node('User', var='n'),
var='r',
directed=False)
assert str(Create(rel)) == 'CREATE (m)-[r:`KNOWS`]-(n)'
def test_full_relationship_create():
expected_query = ('MATCH (m:`User`)\n'
'MATCH (n:`User`)\n'
'CREATE (m)-[rel:`KNOWS`]->(n)')
user_m = Node('User', name=Property(), var='m')
user_n = user_m.copy(var='n')
rel = Relationship('KNOWS', user_m, user_n)
query = Match(user_m) & Match(user_n) & Create(rel)
assert str(query) == expected_query
assert len(query.params) == 0
def test_merge():
kev = Node('Person', name='Kevin', var='kev').bind('name')
ali = Node('Person', name='Ali', var='ali').bind('name')
rel = Relationship('LOVES', kev, ali, duration='forever').bind('duration')
expected_stmt = [
'MATCH (kev:`Person`)',
' WHERE kev.name = {kev_name}',
'MATCH (ali:`Person`)',
' WHERE ali.name = {ali_name}',
'MERGE (kev)-[rel:`LOVES` {duration: {rel_duration}}]->(ali)'
]
query = Match(kev) & Match(ali) & Merge(rel)
assert str(query) == '\n'.join(expected_stmt)
assert len(query.params) == 3
assert 'kev_name' in query.params
assert query.params['kev_name'] == 'Kevin'
assert 'ali_name' in query.params
assert query.params['ali_name'] == 'Ali'
assert 'rel_duration' in query.params
assert query.params['rel_duration'] == 'forever'
def test_full_match():
expected_stmt = [
'MATCH (m:`Person`)',
' WHERE m.name = {m_name}',
'MATCH (n:`Person`)',
' WHERE n.name = {n_name}',
'MATCH (m)-[rel:`KNOWS`]->(n)',
]
person_m = Node('Person', name='Alice', var='m').bind('name')
person_n = person_m.copy(name='Bob', var='n')
knows = Relationship('KNOWS', person_m, person_n)
match = Match(person_m) & Match(person_n) & Match(knows)
assert str(match) == '\n'.join(expected_stmt)
assert len(match.params) == 2
assert 'm_name' in match.params
assert match.params['m_name'] == 'Alice'
assert 'n_name' in match.params
assert match.params['n_name'] == 'Bob'
match.return_().order_by(person_n['name']).skip(1).limit(1)
expected_stmt += [
'RETURN *',
'ORDER BY n.name',
'SKIP 1',
'LIMIT 1',
]
assert str(match) == '\n'.join(expected_stmt)
assert len(match.params) == 2
assert 'm_name' in match.params
assert match.params['m_name'] == 'Alice'
assert 'n_name' in match.params
assert match.params['n_name'] == 'Bob'
expected_stmt[-3] += ' DESC'
for _ in range(3):
match.pop()
match.order_by(person_n['name'], desc=True).skip(1).limit(1)
assert str(match) == '\n'.join(expected_stmt)
assert len(match.params) == 2
assert 'm_name' in match.params
assert match.params['m_name'] == 'Alice'
assert 'n_name' in match.params
assert match.params['n_name'] == 'Bob'
def test_create_relationship():
rel = Relationship('KNOWS', Node('User'), Node('User'))
with pytest.raises(ValueError):
create = Create(rel)
rel.end_node.var = 'end_node'
assert str(Create(rel)) == 'CREATE (node)-[rel:`KNOWS`]->(end_node)'
def test_create_relation_to_nowhere():
rel = Relationship('KNOWS', Node('User'))
with pytest.raises(DetachedObjectError):
create = Create(rel)
def test_relationship_set_once():
rel = Relationship(None)
rel.type = 'X'
rel.start_node = Node('x')
rel.end_node = Node('y')
with pytest.raises(ImmutableAttributeError):
rel.directed = False
with pytest.raises(ImmutableAttributeError):
rel.type = 'Y'
with pytest.raises(ImmutableAttributeError):
rel.start_node = Node('a')
with pytest.raises(ImmutableAttributeError):
rel.end_node = Node('b')
rel = Relationship('X')
with pytest.raises(ImmutableAttributeError):
rel.type = 'Y'
rel = Relationship('X', Node('a'))
with pytest.raises(ImmutableAttributeError):
rel.start_node = Node('a')
rel = Relationship('X', Node('a'), Node('b'))
with pytest.raises(ImmutableAttributeError):
rel.end_node = Node('a')
with pytest.raises(ImmutableAttributeError):
del rel.type
with pytest.raises(ImmutableAttributeError):
del rel.directed
with pytest.raises(ImmutableAttributeError):
del rel.start_node
with pytest.raises(ImmutableAttributeError):
del rel.end_node
def test_optional_match():
person_m = Node('Person', var='m')
person_n = person_m.copy(var='n')
rel = Relationship(None, person_m, person_n)
match = Match(rel, optional=True)
assert str(match) == 'OPTIONAL MATCH (m)-[rel]->(n)'
def test_matching_anonymous_relationship():
person_m = Node('Person', var='m')
person_n = person_m.copy(var='n')
rel = Relationship(None, person_m, person_n)
match = Match(rel)
assert str(match) == 'MATCH (m)-[rel]->(n)'