12.2. Scalar functions

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12.2.1. LENGTH

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.

MATCH p=(a)-->(b)-->(c)
WHERE a.name='Alice'
RETURN length(p)

The length of the path p is returned by the query.

Result

length(p)
3 rows
`2`
`2`
`2`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 match p=(a)-->(b)-->(c) where a.name='Alice' return length(p)

12.2.2. TYPE

Returns a string representation of the relationship type.

Syntax: TYPE( relationship )

Arguments:

relationship: A relationship.

Query.

MATCH (n)-[r]->()
WHERE n.name='Alice'
RETURN type(r)

The relationship type of r is returned by the query.

Result

type(r)
2 rows
`"KNOWS"`
`"KNOWS"`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 match (n)-[r]->() where n.name='Alice' return type(r)

12.2.3. ID

Returns the id of the relationship or node.

Syntax: ID( property-container )

Arguments:

property-container: A node or a relationship.

Query.

MATCH (a)
RETURN id(a)

This returns the node id for three nodes.

Result

id(a)
5 rows
`0`
`1`
`2`
`3`
`4`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 match (a) return id(a)

12.2.4. COALESCE

Returns the first non-NULL value in the list of expressions passed to it. In case all arguments are NULL, NULL will be returned.

Syntax: COALESCE( expression [, expression]* )

Arguments:

expression: The expression that might return NULL.

Query.

MATCH (a)
WHERE a.name='Alice'
RETURN coalesce(a.hairColor, a.eyes)

Result

coalesce(a.hairColor, a.eyes)
1 row
`"brown"`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 match (a) where a.name='Alice' return coalesce(a.hairColor, a.eyes)

12.2.5. HEAD

HEAD returns the first element in a collection.

Syntax: HEAD( expression )

Arguments:

expression: This expression should return a collection of some kind.

Query.

MATCH (a)
WHERE a.name='Eskil'
RETURN a.array, head(a.array)

The first node in the path is returned.

Result

a.array	head(a.array)
1 row
`["one","two","three"]`	`"one"`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 match (a) where a.name='Eskil' return a.array, head(a.array)

12.2.6. LAST

LAST returns the last element in a collection.

Syntax: LAST( expression )

Arguments:

expression: This expression should return a collection of some kind.

Query.

MATCH (a)
WHERE a.name='Eskil'
RETURN a.array, last(a.array)

The last node in the path is returned.

Result

a.array	last(a.array)
1 row
`["one","two","three"]`	`"three"`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 match (a) where a.name='Eskil' return a.array, last(a.array)

12.2.7. TIMESTAMP

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.

RETURN timestamp()

The time in milliseconds is returned.

Result

timestamp()
1 row
`1391433202560`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 return timestamp()

12.2.8. STARTNODE

STARTNODE returns the starting node of a relationship

Syntax: STARTNODE( relationship )

Arguments:

relationship: An expression that returns a relationship

Query.

MATCH (x:foo)-[r]-()
RETURN startNode(r)

Result

startNode(r)
2 rows
`Node[2]{name:"Alice",age:38,eyes:"brown"}`
`Node[2]{name:"Alice",age:38,eyes:"brown"}`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 MATCH (x:foo)-[r]-() return startNode(r)

12.2.9. ENDNODE

ENDNODE returns the end node of a relationship

Syntax: ENDNODE( relationship )

Arguments:

relationship: An expression that returns a relationship

Query.

MATCH (x:foo)-[r]-()
RETURN endNode(r)

Result

endNode(r)
2 rows
`Node[3]{name:"Bob",age:25,eyes:"blue"}`
`Node[4]{name:"Charlie",age:53,eyes:"green"}`

Try this query live. create (_0 {`age`:54, `eyes`:"brown", `name`:"Daniel"}) create (_1:`Spouse` {`age`:41, `array`:["one", "two", "three"], `eyes`:"blue", `name`:"Eskil"}) create (_2:`foo`:`bar` {`age`:38, `eyes`:"brown", `name`:"Alice"}) create (_3 {`age`:25, `eyes`:"blue", `name`:"Bob"}) create (_4 {`age`:53, `eyes`:"green", `name`:"Charlie"}) create _2-[:`KNOWS`]->_3 create _2-[:`KNOWS`]->_4 create _3-[:`KNOWS`]->_0 create _3-[:`MARRIED`]->_1 create _4-[:`KNOWS`]->_0 MATCH (x:foo)-[r]-() return endNode(r)