all() (graph function)

The all() graph function evaluates a condition for each edge or inner node along a variable length path.

Syntax

all(edge, condition)

all(inner_nodes(edge), condition)

Parameters

Returns

Returns true if the condition evaluates to true for each edge or inner node, when inner_nodes is used, in the variable length edge. Otherwise, it returns false.

For zero length paths, the condition evaluates to true.

Examples

The following example shows how to use the graph-match operator with the all() function to find all round-trip paths between two stations in a transportation network. It uses a different line for each direction. The query constructs a graph from the connections data, finding all paths up to five connections long that use the "red" line for the outward route, and the "blue" line for the return route. The all() function ensures that all edges in the variable length edge are part of the same line, either "red" or "blue".

let connections = datatable(from_station:string, to_station:string, line:string) 
[ 
  "Central", "North", "red",
  "North", "Central", "red", 
  "Central", "South",  "red", 
  "South", "Central",  "red", 
  "South", "South-West", "red", 
  "South-West", "South", "red", 
  "South-West", "West", "red", 
  "West", "South-West", "red", 
  "Central", "East", "blue", 
  "East", "Central", "blue", 
  "Central", "West", "blue",
  "West", "Central", "blue",
]; 
connections 
| make-graph from_station --> to_station with_node_id=station
| graph-match (start)-[outward*1..5]->(destination)-[return*1..5]->(start)
  where start.station != destination.station and 
        all(outward, line == "red") and
        all(return, line == "blue") 
  project from = start.station, 
          outward_stations = strcat_array(map(inner_nodes(outward), station), "->"), 
          to = destination.station, 
          return_stations = strcat_array(map(inner_nodes(return), station), "->"), 
          back=start.station

Output

The following example shows how to use the graph-shortest-paths operator with the all() and inner_nodes functions to find a path between two stations in a transportation network. The query constructs a graph from the connections data and finds the shortest path from the "South-West" station to the "North" station, passing through stations where Wi-Fi is available.

let connections = datatable(from_station:string, to_station:string, line:string) 
[ 
  "Central", "North", "red",
  "North", "Central", "red", 
  "Central", "South",  "red", 
  "South", "Central",  "red", 
  "South", "South-West", "red", 
  "South-West", "South", "red", 
  "South-West", "West", "red", 
  "West", "South-West", "red", 
  "Central", "East", "blue", 
  "East", "Central", "blue", 
  "Central", "West", "blue",
  "West", "Central", "blue",
]; 
let stations = datatable(station:string, wifi: bool) 
[ 
  "Central", true,
  "North", false,
  "South", false,
  "South-West", true,
  "West", true,
  "East", false
];
connections 
| make-graph from_station --> to_station with stations on station
| graph-shortest-paths (start)-[connections*2..5]->(destination)
  where start.station == "South-West" and
        destination.station == "North" and 
        all(inner_nodes(connections), wifi)
  project from = start.station, 
          stations = strcat_array(map(inner_nodes(connections), station), "->"), 
          to = destination.station

Output

Related content

• Graph operators
• graph-match operator
• graph-shortest-paths operator
• inner_nodes()