ORDER BY

Overview

The ORDER BY statement allows you to sort the intermediate result table or output table based on the specified items.

Syntax
<order by statement> ::= 
  "ORDER BY" <sort specification> [ { "," <sort specification> }... ]

<sort specification> ::=
  <value expression> [ "ASC" | "DESC" ] [ "NULLS FIRST" | "NULLS LAST" ]

Details

• ASC (ascending) is applied by default. To reverse the order, you can explicitly use the DESC (descending) keyword.
• NULLS FIRST and NULLS LAST can be used to control whether null values appear before or after non-null values. When null ordering is not explicitly specified:
  • NULLS LAST is applied by default when ordering in the ASC order.
  • NULLS FIRST is applied by default when ordering in the DESC order.

Example Graph

GQL
INSERT (p1:Paper {_id:'P1', title:'Efficient Graph Search', score:6, author:'Alex', publisher:'PulsePress'}),
       (p2:Paper {_id:'P2', title:'Optimizing Queries', score:9, author:'Alex'}),
       (p3:Paper {_id:'P3', title:'Path Patterns', score:7, author:'Zack', publisher:'BrightLeaf'}),
       (p1)-[:Cites {weight:2}]->(p2),
       (p2)-[:Cites {weight:1}]->(p3)

Ordering by Property

GQL
MATCH (n:Paper)
ORDER BY n.score
RETURN n.title, n.score

Result:

Ordering by Node or Edge Variable

When a node or edge variable is specified, it is sorted on the _id of the nodes or edges.

GQL
MATCH (n:Paper)
RETURN n.title, element_id(n) ORDER BY n

Result:

Ordering by Expression

GQL
MATCH p = (:Paper)->{1,2}(:Paper)
RETURN p, path_length(p) AS length ORDER BY length DESC

Result:

Multi-level Ordering

When there are multiple ordering specifications, it is sorted by the first specification listed, and for equals values, go to the next specification, and so on.

GQL
MATCH (n:Paper)
RETURN n.title, n.author, n.score 
ORDER BY n.author DESC, n.score

Result:

Discarding and Retaining Records After Ordering

You may use the SKIP or LIMIT statement after ORDER BY to skip a specified number of rows from the top, or to limit the number of rows retained.

Return titles of the two papers with the second and third highest scores:

GQL
MATCH (n:Paper)
RETURN n.title, n.score
ORDER BY n.score DESC SKIP 1 LIMIT 2

Result:

Null Ordering

Return titles of the two papers with the second and third highest scores, ensuring null values appear at the front if applicable:

GQL
MATCH (n:Paper)
RETURN n.title, n.publisher
ORDER BY n.publisher NULLS FIRST

Result: