CALL executes operations against the query result of each subquery, NOT all the result of a query command. It wraps query commands and the operations in curly braces {}, passes in the alias that triggers each subquery using a WITH clause and passes out the result of each subquery using a RETURN clause.

Syntax:
CALL {
  WITH <alias_In>, <alias_In>, ...
  ...
  RETURN <expression> as <alias_Out>, <expression> as <alias_Out>, ...
} Input:

• <alias_In>: The alias that triggers the subquery
• <expression>: The return value of the subquery
• <alias_Out>: The alias of return value of the subquery, optional when <expression> is alias

For instance, skip the first row of each subquery result p:

find().nodes([1, 5]) as nodes
call {
  with nodes
  n(nodes).e()[:2].n() as p
  skip 1
  return p as path
}
return path

Sample graph: (to be used for the following examples)

create().node_schema("country").node_schema("movie").node_schema("director").edge_schema("filmedIn").edge_schema("direct")
create().node_property(@*, "name")
insert().into(@country).nodes([{_id:"C001", _uuid:1, name:"France"}, {_id:"C002", _uuid:2, name:"USA"}])
insert().into(@movie).nodes([{_id:"M001", _uuid:3, name:"Léon"}, {_id:"M002", _uuid:4, name:"The Terminator"}, {_id:"M003", _uuid:5, name:"Avatar"}])
insert().into(@director).nodes([{_id:"D001", _uuid:6, name:"Luc Besson"}, {_id:"D002", _uuid:7, name:"James Cameron"}])
insert().into(@filmedIn).edges([{_uuid:1, _from_uuid:3, _to_uuid:1}, {_uuid:2, _from_uuid:4, _to_uuid:1}, {_uuid:3, _from_uuid:3, _to_uuid:2}, {_uuid:4, _from_uuid:4, _to_uuid:2}, {_uuid:5, _from_uuid:5, _to_uuid:2}])
insert().into(@direct).edges([{_uuid:6, _from_uuid:6, _to_uuid:3}, {_uuid:7, _from_uuid:7, _to_uuid:4}, {_uuid:8, _from_uuid:7, _to_uuid:5}])

Common Usage

Example: Not using GROUP BY, find how many movies are filmed in each country

find().nodes({@country}) as nodes
call { 
  with nodes
  n(nodes).e().n({@movie} as n)
  return count(n) as number
}
return table(nodes.name, number)

| nodes.name | number |
|------------|--------|
| France     | 2      |
| USA        | 3      |