LET Value Expression

The LET value expression allows you to define variables and use them immediately in an expression. It can be used for improving readability and simplifying more complex expressions.

<let value expression> ::=
 "LET" <let variable definition list> "IN" <value expression> "END"

<let variable definition list> ::=
  <let variable definition> [ { "," <let variable definition> }... ]

<let variable definition> ::= <binding variable> "=" <value expression>

Example Graph

The following examples run against this graph:

To create this graph, run the following query against an empty graph:

INSERT (p1:Paper {_id:'P1', title:'Efficient Graph Search', score:6}),
       (p2:Paper {_id:'P2', title:'Optimizing Queries', score:9}),
       (p3:Paper {_id:'P3', title:'Path Patterns', score:7}),
       (p1)-[:Cites]->(p2),
       (p2)-[:Cites]->(p3)

Examples

RETURN LET x = 2, y = 1 IN x^2+y END AS result

Result:

MATCH (n:Paper)
RETURN n.title, LET plus = 1 IN n.score + plus END AS newScore

Result: