字符串运算符

Nebula Graph支持使用字符串运算符进行连接、搜索、匹配运算。支持的运算符如下。

名称说明
+连接字符串。
CONTAINS在字符串中执行搜索。
(NOT) IN字符串是否匹配某个值。
(NOT) STARTS WITH在字符串的开头执行匹配。
(NOT) ENDS WITH在字符串的结尾执行匹配。
正则表达式通过正则表达式匹配字符串。

Note

所有搜索或匹配都区分大小写。

示例

+

  1. nebula> RETURN 'a' + 'b';
  2. +-----------+
  3. | ("a"+"b") |
  4. +-----------+
  5. | "ab"      |
  6. +-----------+
  7. nebula> UNWIND 'a' AS a UNWIND 'b' AS b RETURN a + b;
  8. +-------+
  9. | (a+b) |
  10. +-------+
  11. | "ab"  |
  12. +-------+

CONTAINS

CONTAINS要求待运算的左右两边都是字符串类型。

  1. nebula> MATCH (s:player)-[e:serve]->(t:team) WHERE id(s) == "player101" \
  2.         AND t.name CONTAINS "ets" RETURN s.name, e.start_year, e.end_year, t.name;
  3. +---------------+--------------+------------+-----------+
  4. | s.name        | e.start_year | e.end_year | t.name    |
  5. +---------------+--------------+------------+-----------+
  6. | "Tony Parker" | 2018         | 2019       | "Hornets" |
  7. +---------------+--------------+------------+-----------+
  9. nebula> GO FROM "player101" OVER serve WHERE (STRING)properties(edge).start_year CONTAINS "19" AND \
  10.         properties($^).name CONTAINS "ny" \
  11.         YIELD properties($^).name, properties(edge).start_year, properties(edge).end_year, properties($$).name;
  12. +---------------------+-----------------------------+---------------------------+---------------------+
  13. | properties($^).name | properties(EDGE).start_year | properties(EDGE).end_year | properties($$).name |
  14. +---------------------+-----------------------------+---------------------------+---------------------+
  15. | "Tony Parker"       | 1999                        | 2018                      | "Spurs"             |
  16. +---------------------+-----------------------------+---------------------------+---------------------+
  18. nebula> GO FROM "player101" OVER serve WHERE !(properties($$).name CONTAINS "ets") \
  19.         YIELD properties($^).name, properties(edge).start_year, properties(edge).end_year, properties($$).name;
  20. +---------------------+-----------------------------+---------------------------+---------------------+
  21. | properties($^).name | properties(EDGE).start_year | properties(EDGE).end_year | properties($$).name |
  22. +---------------------+-----------------------------+---------------------------+---------------------+
  23. | "Tony Parker"       | 1999                        | 2018                      | "Spurs"             |
  24. +---------------------+-----------------------------+---------------------------+---------------------+

(NOT) IN

  1. nebula> RETURN  1 IN [1,2,3], "Yao" NOT IN ["Yi", "Tim", "Kobe"], NULL IN ["Yi", "Tim", "Kobe"];
  2. +----------------+------------------------------------+-------------------------------+
  3. | (1 IN [1,2,3]) | ("Yao" NOT IN ["Yi","Tim","Kobe"]) | (NULL IN ["Yi","Tim","Kobe"]) |
  4. +----------------+------------------------------------+-------------------------------+
  5. | true           | true                               | __NULL__                      |
  6. +----------------+------------------------------------+-------------------------------+

(NOT) STARTS WITH

  1. nebula> RETURN 'apple' STARTS WITH 'app', 'apple' STARTS WITH 'a', 'apple' STARTS WITH toUpper('a');
  2. +-----------------------------+---------------------------+------------------------------------+
  3. | ("apple" STARTS WITH "app") | ("apple" STARTS WITH "a") | ("apple" STARTS WITH toUpper("a")) |
  4. +-----------------------------+---------------------------+------------------------------------+
  5. | true                        | true                      | false                              |
  6. +-----------------------------+---------------------------+------------------------------------+
  8. nebula> RETURN 'apple' STARTS WITH 'b','apple' NOT STARTS WITH 'app';
  9. +---------------------------+---------------------------------+
  10. | ("apple" STARTS WITH "b") | ("apple" NOT STARTS WITH "app") |
  11. +---------------------------+---------------------------------+
  12. | false                     | false                           |
  13. +---------------------------+---------------------------------+

(NOT) ENDS WITH

  1. nebula> RETURN 'apple' ENDS WITH 'app', 'apple' ENDS WITH 'e', 'apple' ENDS WITH 'E', 'apple' ENDS WITH 'b';
  2. +---------------------------+-------------------------+-------------------------+-------------------------+
  3. | ("apple" ENDS WITH "app") | ("apple" ENDS WITH "e") | ("apple" ENDS WITH "E") | ("apple" ENDS WITH "b") |
  4. +---------------------------+-------------------------+-------------------------+-------------------------+
  5. | false                     | true                    | false                   | false                   |
  6. +---------------------------+-------------------------+-------------------------+-------------------------+

正则表达式

Note

当前仅opencypher兼容语句（MATCH、WITH等）支持正则表达式，原生nGQL语句（FETCH、GO、LOOKUP等）不支持正则表达式。

Nebula Graph支持使用正则表达式进行过滤，正则表达式的语法是继承自std::regex，用户可以使用语法=~ '<regexp>'进行正则表达式匹配。例如：

  1. nebula> RETURN "384748.39" =~ "\\d+(\\.\\d{2})?";
  2. +--------------------------------+
  3. | ("384748.39"=~"\d+(\.\d{2})?") |
  4. +--------------------------------+
  5. | true                           |
  6. +--------------------------------+
  8. nebula> MATCH (v:player) WHERE v.name =~ 'Tony.*' RETURN v.name;
  9. +---------------+
  10. | v.name        |
  11. +---------------+
  12. | "Tony Parker" |
  13. +---------------+

最后更新: November 1, 2021