This section is showing how to create some of the named pretty graphs on Wikipedia.
The graph is created by first creating a center node, and then once per element in the range, creates a leaf node and connects it to the center.
Query.
CREATE (center) FOREACH (x IN range(1,6)| CREATE (leaf),(center)-[:X]->(leaf)) RETURN id(center) AS id;
The query returns the id of the center node.
This graph is created in a number of steps:
Query.
CREATE (center)
FOREACH (x IN range(1,6)| CREATE (leaf { count:x }),(center)-[:X]->(leaf))
WITH center
MATCH (large_leaf)<--(center)-->(small_leaf)
WHERE large_leaf.count = small_leaf.count + 1
CREATE (small_leaf)-[:X]->(large_leaf)
WITH center, min(small_leaf.count) AS min, max(large_leaf.count) AS max
MATCH (first_leaf)<--(center)-->(last_leaf)
WHERE first_leaf.count = min AND last_leaf.count = max
CREATE (last_leaf)-[:X]->(first_leaf)
RETURN id(center) AS id
The query returns the id of the center node.
For this graph, a root node is created, and used to hang a number of nodes from. Then, two nodes are selected, hanging from the center, with the requirement that the id of the first is less than the id of the next. This is to prevent double relationships and self relationships. Using said match, relationships between all these nodes are created. Lastly, the center node and all relationships connected to it are removed.
Query.
CREATE (center)
FOREACH (x IN range(1,6)| CREATE (leaf { count : x }),(center)-[:X]->(leaf))
WITH center
MATCH (leaf1)<--(center)-->(leaf2)
WHERE id(leaf1)<id(leaf2)
CREATE (leaf1)-[:X]->(leaf2)
WITH center
MATCH (center)-[r]->()
DELETE center,r;
Nothing is returned by this query.
Result
| Nodes created: 7 |
|---|
| Relationships created: 21 |
| Properties set: 6 |
| Nodes deleted: 1 |
| Relationships deleted: 6 |
|
This query first creates a center node, and then once per element in the range, creates a cycle graph and connects it to the center
Query.
CREATE (center) FOREACH (x IN range(1,3)| CREATE (leaf1),(leaf2),(center)-[:X]->(leaf1),(center)-[:X]->(leaf2), (leaf1)-[:X]->(leaf2)) RETURN ID(center) AS id
The id of the center node is returned by the query.
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