反转MQL查询

Chapter 3 of the MQL reference（特别是第3.2.6节）讨论颠倒查询以获得不同结构中的相同数据，以简化查询或按摩数据以返回与您自己类似的结构。反转MQL查询

于是我开始用下面的查询：

https://api.freebase.com/api/service/mqlread?query={"query":{"type":"/automotive/model","name":"Ford Taurus","generations":[]}}

可读的版本：

{ 
    "type":"/automotive/model", 
    "name":"Ford Taurus", 
    "generations":[] 
}

结果：

{ 
    "code": "/api/status/ok", 
    "result": { 
    "generations": [ 
     "First Generation Ford Taurus", 
     "Second Generation Ford Taurus", 
     "Fifth Generation Ford Taurus", 
     "Sixth Generation Ford Taurus", 
     "Fourth Generation Ford Taurus", 
     "Third Generation Ford Taurus" 
    ], 
    "name": "Ford Taurus", 
    "type": "/automotive/model" 
    }, 
    "status": "200 OK", 
    "transaction_id": "cache;cache04.p01.sjc1:8101;2013-04-25T22:05:58Z;0012" 
}

但我想使查询生成为中心的，所以我修改它像这样：

https://api.freebase.com/api/service/mqlread?query={"query":[{"type":"/automotive/generation","model":"Ford Taurus","name":null}]}

可读的版本：

[{ 
    "type":"/automotive/generation", 
    "model":"Ford Taurus", 
    "name":null 
}]

结果：

{ 
    "code": "/api/status/ok", 
    "result": [ 
    { 
     "model": "Ford Taurus", 
     "name": "First Generation Ford Taurus", 
     "type": "/automotive/generation" 
    }, 
    { 
     "model": "Ford Taurus", 
     "name": "Third Generation Ford Taurus", 
     "type": "/automotive/generation" 
    } 
    ], 
    "status": "200 OK", 
    "transaction_id": "cache;cache01.p01.sjc1:8101;2013-04-25T23:00:35Z;0010" 
}

我倒查询只返回两代人！请帮我弄清楚这是为什么。

来源

2013-04-25 adam_0

如果您查看Automobile Generation的Freebase架构页面，您会看到model属性已被弃用，并被替换为型号属性。做出这样的转变对您的查询：

[{ 
    "type": "/automotive/generation", 
    "models": "Ford Taurus", 
    "name": null 
}]

带给你预期的结果集：

[ 
    { 
    "models": "Ford Taurus", 
    "name": "First Generation Ford Taurus", 
    "type": "/automotive/generation" 
    }, 
    { 
    "models": "Ford Taurus", 
    "name": "Second Generation Ford Taurus", 
    "type": "/automotive/generation" 
    }, 
    { 
    "models": "Ford Taurus", 
    "name": "Fifth Generation Ford Taurus", 
    "type": "/automotive/generation" 
    }, 
    { 
    "models": "Ford Taurus", 
    "name": "Sixth Generation Ford Taurus", 
    "type": "/automotive/generation" 
    }, 
    { 
    "models": "Ford Taurus", 
    "name": "Fourth Generation Ford Taurus", 
    "type": "/automotive/generation" 
    }, 
    { 
    "models": "Ford Taurus", 
    "name": "Third Generation Ford Taurus", 
    "type": "/automotive/generation" 
    } 
]

来源

2013-04-25 23:27:53

哇！我偶然发现它（我正在研究* models *模式，所以我不知道* model *）。谢谢！ – 2013-04-25 23:38:38

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