def merge(self, graph, merge_properties=None, batch_size=None):
"""
Merge nodes from NodeSet on merge properties.
:param merge_properties: The merge properties.
"""
log.debug('Merge NodeSet on {}'.format(merge_properties))
if not batch_size:
batch_size = self.batch_size
if not merge_properties:
merge_properties = self.merge_keys
log.debug('Batch Size: {}'.format(batch_size))
query = nodes_merge_unwind(self.labels, merge_properties)
log.debug(query)
i = 1
for batch in chunks(self.node_properties(), size=batch_size):
batch = list(batch)
log.debug('Batch {}'.format(i))
log.debug(batch[0])
graph.run(query, props=batch)
i += 1
def test_query_multiple_labels(self):
test_labels = ['Foo', 'Bar']
query = nodes_merge_unwind(test_labels, ['sid'])
expected_query = """UNWIND $props AS properties
MERGE (n:Foo:Bar { sid: properties.sid } )
ON CREATE SET n = properties
ON MATCH SET n += properties"""
assert query == expected_query
def test_query_single_label(self):
test_label = ['Foo']
query = nodes_merge_unwind(test_label, ['sid'])
expected_query = """UNWIND $props AS properties
MERGE (n:Foo { sid: properties.sid } )
ON CREATE SET n = properties
ON MATCH SET n += properties"""
assert query == expected_query
def test_nodes_are_created(self, graph, clear_graph):
query = nodes_merge_unwind(['Foo'], ['testid'])
graph.run(query, props=[{'testid': 1, 'key': 'newvalue'}])
results = list(graph.run("MATCH (n:Foo) RETURN n"))
first_row = results[0]
first_row_first_element = first_row[0]
assert len(results) == 1
assert first_row_first_element['testid'] == 1
assert first_row_first_element['key'] == 'newvalue'
def test_own_param_name(self):
test_labels = ['Foo', 'Bar']
merge_props = ['sid', 'other']
query = nodes_merge_unwind(test_labels,
merge_props,
property_parameter='nodes')
expected_query = """UNWIND $nodes AS properties
MERGE (n:Foo:Bar { sid: properties.sid, other: properties.other } )
ON CREATE SET n = properties
ON MATCH SET n += properties"""
assert query == expected_query
def merge(self,
graph,
merge_properties=None,
batch_size=None,
raise_on_result_count_deviation=False):
"""
Merge nodes from NodeSet on merge properties.
:param merge_properties: The merge properties.
:raise_on_result_count_deviation: boolean. Raise if less nodes were processed on DB side as sended with the query. This can happen in parallel processing environments. set Nodeset.failed_batch_handler(error,query,batch) to catch single failed batches
"""
log.debug('Merge NodeSet on {}'.format(merge_properties))
if not batch_size:
batch_size = self.batch_size
if not merge_properties:
merge_properties = self.merge_keys
log.debug('Batch Size: {}'.format(batch_size))
query = nodes_merge_unwind(self.labels, merge_properties)
log.debug(query)
i = 1
for batch in chunks(self.node_properties(), size=batch_size):
batch = list(batch)
log.debug('Batch {}'.format(i))
log.debug(batch[0])
try:
tx = graph.begin()
tx.run(query, props=batch)
result = tx.run(query, props=batch)
tx.commit()
count = result.data()[0]["cnt"]
if raise_on_result_count_deviation and count < len(batch):
raise MissingNodesEx(
"Excepted {} Nodes to be inserted, got {}", len(batch),
count)
except Exception as e:
if self.failed_batch_handler is not None:
self.failed_batch_handler(self, e, query, batch)
else:
raise
i += 1
def test_nodes_are_merged(self, graph, clear_graph):
graph.run(
"CREATE (n:Foo) SET n.testid = 1, n.key = 'value', n.other = 'other_value'"
)
query = nodes_merge_unwind(['Foo'], ['testid'])
graph.run(query, props=[{'testid': 1, 'key': 'newvalue'}])
results = list(graph.run("MATCH (n:Foo) RETURN n"))
first_row = results[0]
first_row_first_element = first_row[0]
assert len(results) == 1
assert first_row_first_element['testid'] == 1
assert first_row_first_element['key'] == 'newvalue'
# assert other value did not change
assert first_row_first_element['other'] == 'other_value'
