问题
Sample Data:
Query to create sample data
g.addV("Test1").property("title", "A")
g.addV("Test2").property("title", "B")
g.addV("Test3").property("title", "C")
g.addV("Test4").property("title", "D")
g.V().has("Test1", "title", "A").addE("rel").to(g.V().has("Test2", "title", "B"))
g.V().has("Test2", "title", "B").addE("rel").to(g.V().has("Test3", "title", "C"))
g.V().has("Test3", "title", "C").addE("rel").to(g.V().has("Test4", "title", "D"))
Query:
- Find how
A
is connected toA
Expected answer: Not Connected
My Queries:
g.V().has("Test1", "title", "A").as("nodes")
.repeat(both().as("nodes"))
.emit(hasLabel("Test1")).hasLabel("Test1")
.limit(25)
.project("val").by(select(all, "nodes").unfold().values("title").fold())
Results (limit 25
)
{'val': ['A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'D', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'C', 'D', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'C', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'C', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'A', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'B', 'A', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'C', 'D', 'C', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'C', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'C', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'A', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'A', 'B', 'A', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'D', 'C', 'D', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'D', 'C', 'B', 'C', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'D', 'C', 'B', 'A', 'B', 'A']}
{'val': ['A', 'B', 'C', 'D', 'C', 'B', 'C', 'D', 'C', 'B', 'A']}
Okay lets try dedup
g.V().has("Test1", "title", "A").as("nodes")
.repeat(both().as("nodes").dedup())
.emit(hasLabel("Test1")).hasLabel("Test1")
.project("val").by(select(all, "nodes").unfold().values("title").fold())
Result
{'val': ['A', 'B', 'A']}
There is exactly one edge between A
and B
. Then why is Gremlin traversing on the same edge? Am I writing the wrong query?
How Cypher Query behaves seems to be the correct way to be
MATCH p=((n:Test1)-[*]-(m:Test1)) RETURN p
Gremlin Server version: 3.3.1
回答1:
Looks like all you want is non-cyclic paths:
g.V().has("Test1", "title", "A").
repeat(both().simplePath()).
until(hasLabel("Test1")).
path().
by("title")
来源:https://stackoverflow.com/questions/51967983/tinkerpop-gremlin-revisiting-visited-edges