ORIENTDB：遍歷/具有屬性的邊

Question

我在圖形數據庫中有一個與應用程序許可相關的問題。 結構如下...我必須閱讀與節點相關的用戶角色。 節點按層次結構組織，角色作為邊緣提供，其中包含類型屬性和關系User-> UserRole {type：xyz}-> Node

create class User extends V    
create class Node extends V  
create class has_father extends E
create class UserRole extends E

create vertex User set name = 'u1'
create vertex User set name = 'u2'
create vertex User set name = 'u3'   



create vertex Node set name = 'n1'
create vertex Node set name = 'n11'
create vertex Node set name = 'n12'
create vertex Node set name = 'n111'    
create vertex Node set name = 'n112'
create vertex Node set name = 'n1111'
create vertex Node set name = 'n1112'
create vertex Node set name = 'n11111'
create vertex Node set name = 'n11112'

create edge has_father from (select from Node where name = 'n11') to (select from Node where name = 'n1')
create edge has_father from (select from Node where name = 'n12') to (select from Node where name = 'n1')
create edge has_father from (select from Node where name = 'n111') to (select from Node where name = 'n11')
create edge has_father from (select from Node where name = 'n112') to (select from Node where name = 'n11')
create edge has_father from (select from Node where name = 'n1111') to (select from Node where name = 'n111')
create edge has_father from (select from Node where name = 'n1112') to (select from Node where name = 'n111')
create edge has_father from (select from Node where name = 'n11111') to (select from Node where name = 'n1111')
create edge has_father from (select from Node where name = 'n11112') to (select from Node where name = 'n1111')

create edge UserRole from (select from User where name = 'u1') to (select from Node where name = 'n1') set type = 'admin'
create edge UserRole from (select from User where name = 'u1') to (select from Node where name = 'n11') set type = 'read'
create edge UserRole from (select from User where name = 'u2') to (select from Node where name = 'n111') set type = 'write'
create edge UserRole from (select from User where name = 'u1') to (select from Node where name = 'n11111') set type = 'test'

實際上，我現在必須從“ n”讀取所有子級，並獲取用戶“ u1”的節點和UserRole：

詢問“ u1”和“ n1”：

n11 read
n12 admin

詢問“ u1”和“ n1111”：

n11111 test
n11112 read

這意味着最多分配了1個UserRole，並且該值可能在樹中被覆蓋。 用戶可能是root級別的管理員，並且只能從n11級別開始讀取。

如何讀取通過父@rid（或過濾器）的子節點以及為特殊用戶計算的角色？

Answer 1

在第二個示例中嘗試使用以下SQL：

select name as Name, $a.type[0] as Role from (select expand(in('has_father')) from (select from Node where name = 'n1111') unwind in)

let $a=(select inE('UserRole').type as type from (
            traverse out('has_father'),in('UserRole') from $parent.$current while out('UserRole').@rid <> #21:0
            ) where in('UserRole').@rid = #21:0
            limit 1
        )

其中＃21：0是u1 @rid。

只要不是那么漂亮，就可以將其插入JS函數並將其參數化。

---