嵌套SPARQL的JSON响应

Question

[我具有如下结构，我目前正在寻求通过SPARQL查询获得这样的JSON响应，我已经尝试了一些类似concat和str的事情，但是dint对我来说很好，它在第三级变得很复杂

我现在添加了我尝试使用JSON-LD进行帧划分的2个帧，它提供了正确的输出，直到第二级的第一级未能扩展数据为止

:Reference xx1:timestamp  "12/15/2020" .
:Reference xx2:logs xxx:log1 .


:log1   rdf:type        xxx:Logs .
:log1   xx1:approver  "xxx:bob" .
:log1   xx1:requester "xxx:daisy" .
:log1   xx1:timestamp  "12/15/2020" .
:log1   xx1:name   "log1" .

:log2   rdf:type        xxx:Logs .
:log2   xx1:approver   "xxx:bob" .
:log2   xx1:requester  "xxx.daisy" .
:log2   xx1:timestamp  "18/15/2020" .
:log2   xx1:name   "log2" .

:bob   rdf:type        xxx:User .
:bob   xx1:name   "bob" .

:daisy   rdf:type        xxx:User .
:daisy   xx1:name   "daisy" .```

Required Response with SPARQL (3 Levels)
[
  {
    "timestamp": "12/15/2020",   
    "logs": [
      { "name": "log1", "timestamp": "12/15/2020"  "approver" : {name: bob },"requester" : {name: bob }},
      { "name": "log2", "timestamp": "12/15/2020"  "approver" : {name: bob },"requester" : {name: bob }},
    ]
  }
]

    JSON-LD FRAMING
FRAME 1
{
   "@context":{
      "XXX":"http://ABC"
   },
   "@type":"xxx:Reference",
   "contains":{
      "@type":"xxx:Log",
      "contains":{
         "@type":"xxx:User"
      }
   }
}


FRAME 2

{
   "@context":{
      "XXX":"http://ABC"
   },
   "@type":"xxx:Reference",
   "contains":{
      "@type":"xxx:Log",
      "hasApprover" :{"@type":"xxx:User"},
      "hasRequester" :{"@type":"xxx:User"}
   }
}

The output that I get is 
Reference [Log 1 {User is expnded}, Log2{User is not expanded}]

What I need is 
Reference [Log 1 {User is expanded}, Log2{User is expanded}]

Answer 1

此JSON-LD框架有助于获得所需的结果

   "@context":{
      "XXX":"http://ABC"
   },
   "@type":"xxx:Reference",
   "contains":{
      "@type":"xxx:Log",
      "hasApprover" :{"@type":"xxx:User","@embed": "@always"},
      "hasRequester" :{"@type":"xxx:User","@embed": "@always"}
   }
}