动态引用Power Query m中的JSON节点

Question

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，并提供节点的名称作为变量，如:

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

但是得到这个错误: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?

Answer 1

Try

(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myFunc:

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