在 Power Query M 中动态引用 JSON 节点

Dynamically referring to JSON node in Power Query M

我有一个从 JSON 文档中提取节点的函数,如下所示:

...
Json  = GetJson(Url),
Value = Json[#"values"]

值对应于 JSON 文档中的实际节点。

我想概括这段代码并提供节点名称作为变量,如:

let myFunc = (parentNodeName as text) =>
...
Json  = GetJson(Url),
Value = Json[parentNodeName]

但是出现此错误: An error occurred in the ‘myFunc’ query. Expression.Error: The field 'parentNodeName' of the record wasn't found.

如何动态引用 JSON 节点?

尝试

(Json, parentNodeName ) =>
let
...
Value = Record.Field(Json,parentNodeName)
in Value

示例代码:

let Json = Json.Document(Web.Contents("http://soundcloud.com/oembed?url=http%3A//soundcloud.com/forss/flickermood&format=json")),
Value=myFunc(Json,"title")
in Value

和我的函数:

(Json, parentNodeName ) =>
let 
Value = Record.Field(Json,parentNodeName)
in Value