List functions¶
| Function | Description |
|---|---|
| keys(expr) | Returns a list containing the string representations for all the property names of a vertex, edge, or map. |
| labels(vertex) | Returns the tags of a vertex. |
| nodes(path) | Returns a list containing all the nodes in a path. |
| range(start, end [, step]) | A list of Integer elements. |
| relationships(path) | Returns a list containing all the relationships in a path. |
| reverse(list) | returns a list in which the order of all elements in the original list have been reversed. |
| tail(list) | returns all the elements, excluding the first one. |
| head(list) | Returns the first element of a list. |
| last(list) | Returns the last element of a list. |
| coalesce(list) | Returns the first not null value in a list. |
| reduce() | See reduce() function. |
Note
If the parameter is NULL, the output is undefined.
Examples¶
nebula> WITH [NULL, 4923, 'abc', 521, 487] AS ids RETURN reverse(ids), tail(ids), head(ids), last(ids), coalesce(ids)
+-----------------------------------+-------------------------+-----------+-----------+---------------+
| reverse(ids) | tail(ids) | head(ids) | last(ids) | coalesce(ids) |
+-----------------------------------+-------------------------+-----------+-----------+---------------+
| [487, 521, "abc", 4923, __NULL__] | [4923, "abc", 521, 487] | __NULL__ | 487 | 4923 |
+-----------------------------------+-------------------------+-----------+-----------+---------------+
nebula> MATCH (a:player)-[r]->() WHERE id(a) == "player100" RETURN labels(a), keys(r)
+------------+----------------------------+
| labels(a) | keys(r) |
+------------+----------------------------+
| ["player"] | ["degree"] |
+------------+----------------------------+
| ["player"] | ["degree"] |
+------------+----------------------------+
| ["player"] | ["end_year", "start_year"] |
+------------+----------------------------+
nebula> MATCH p = (a:player)-[]->(b)-[]->(c:team) WHERE a.name == "Tim Duncan" AND c.name == "Spurs" RETURN nodes(p)
+-----------------------------------------------------------------------------------------------------------------------------------------------+
| nodes(p) |
+-----------------------------------------------------------------------------------------------------------------------------------------------+
| [("player100" :player{age: 42, name: "Tim Duncan"}), ("player101" :player{age: 36, name: "Tony Parker"}), ("team204" :team{name: "Spurs"})] |
+-----------------------------------------------------------------------------------------------------------------------------------------------+
| [("player100" :player{age: 42, name: "Tim Duncan"}), ("player125" :player{age: 41, name: "Manu Ginobili"}), ("team204" :team{name: "Spurs"})] |
+-----------------------------------------------------------------------------------------------------------------------------------------------+
nebula> MATCH p = (a:player)-[]->(b)-[]->(c:team) WHERE a.name == "Tim Duncan" AND c.name == "Spurs" RETURN relationships(p)
+-----------------------------------------------------------------------------------------------------------------------------+
| relationships(p) |
+-----------------------------------------------------------------------------------------------------------------------------+
| [[:follow "player100"->"player101" @0 {degree: 95}], [:serve "player101"->"team204" @0 {end_year: 2018, start_year: 1999}]] |
+-----------------------------------------------------------------------------------------------------------------------------+
| [[:follow "player100"->"player125" @0 {degree: 95}], [:serve "player125"->"team204" @0 {end_year: 2018, start_year: 2002}]] |
+-----------------------------------------------------------------------------------------------------------------------------+
Last update: April 22, 2021