Scalar functions return a single value.
To return or filter on the length of a collection, use the LENGTH() function.
Syntax: LENGTH( collection )
Arguments:
- collection: An expression that returns a collection
Query.
START a=node(3) MATCH p=a-->b-->c RETURN length(p)
The length of the path p is returned by the query.
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start a=node(3) match p=a-->b-->c return length(p)
Returns a string representation of the relationship type.
Syntax: TYPE( relationship )
Arguments:
- relationship: A relationship.
Query.
START n=node(3) MATCH (n)-[r]->() RETURN type(r)
The relationship type of r is returned by the query.
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start n=node(3) match (n)-[r]->() return type(r)
Returns the id of the relationship or node.
Syntax: ID( property-container )
Arguments:
- property-container: A node or a relationship.
Query.
START a=node(3, 4, 5) RETURN ID(a)
This returns the node id for three nodes.
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start a=node(3, 4, 5) return ID(a)
Returns the first non-null value in the list of expressions passed to it.
Syntax: COALESCE( expression [, expression]* )
Arguments:
- expression: The expression that might return null.
Query.
START a=node(3) RETURN coalesce(a.hairColour?, a.eyes?)
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start a=node(3) return coalesce(a.hairColour?, a.eyes?)
HEAD returns the first element in a collection.
Syntax: HEAD( expression )
Arguments:
- expression: This expression should return a collection of some kind.
Query.
START a=node(2) RETURN a.array, head(a.array)
The first node in the path is returned.
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start a=node(2) return a.array, head(a.array)
LAST returns the last element in a collection.
Syntax: LAST( expression )
Arguments:
- expression: This expression should return a collection of some kind.
Query.
START a=node(2) RETURN a.array, last(a.array)
The last node in the path is returned.
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start a=node(2) return a.array, last(a.array)
TIMESTAMP returns the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC. It will return the same value during the whole one query, even if the query is a long running one.
Syntax: TIMESTAMP()
Arguments:
Query.
START n=node(1) RETURN timestamp()
The time in milliseconds.
Try this query live. (1) {"age":54,"eyes":"brown","name":"D"} (2) {"age":41,"array":["one","two","three"],"eyes":"blue","name":"E"} (3) {"age":38,"eyes":"brown","name":"A"} (4) {"age":25,"eyes":"blue","name":"B"} (5) {"age":53,"eyes":"green","name":"C"} (3)-[:KNOWS]->(4) {} (3)-[:KNOWS]->(5) {} (4)-[:KNOWS]->(1) {} (4)-[:MARRIED]->(2) {} (5)-[:KNOWS]->(1) {} start n=node(1) return timestamp()