使用 Power BI / Power Query 從表到 JSON

Question

我需要轉換下表：

轉成JSON格式，如：

{
  "Inputs": {
    "input1": {
      "ColumnNames": [
        "age",
        "workclass",
        "fnlwgt",
        "education",
        "education-num",
        "marital-status",
        "occupation",
        "relationship",
        "race",
        "sex",
        "capital-gain",
        "capital-loss",
        "hours-per-week",
        "native-country"
      ],
      "Values": [
        [
          "0",
          "value",
          "0",
          "value",
          "0",
          "value",
          "value",
          "value",
          "value",
          "value",
          "0",
          "0",
          "0",
          "value"
        ],
        [
          "0",
          "value",
          "0",
          "value",
          "0",
          "value",
          "value",
          "value",
          "value",
          "value",
          "0",
          "0",
          "0",
          "value"
        ]
      ]
    }
  },
  "GlobalParameters": {}
}

這應該用作對 Web 服務的POST請求的正文。

因此，我嘗試將以下函數應用於上表：

(InputData) =>
let
    JsonOutput = Json.FromValue(InputData),
    OutputText = Text.FromBinary(JsonOutput)
in
    OutputText

這是完整的代碼：

let
    Origem = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("HY2xDsIwDET/JTOWGtoSMcIOC0IMVQcrMdSS00huVIm/x2G4e3e64abJ9Wd3cI+KleBTdsshjP5kvGJcSIpuln1vdqedFDKqMiXrl5QhCilHlDaXCrzCGzPL1/pr4UrGG0rD0YfB0JmGZs/V5gT/583N8w8=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [age = _t, workclass = _t, fnlwgt = _t, education = _t, #"education-num" = _t, #"marital-status" = _t, occupation = _t, relationship = _t, race = _t, sex = _t, #"capital-gain" = _t, #"capital-loss" = _t, #"hours-per-week" = _t, #"native-country" = _t]),
    #"Tipo Alterado" = Table.TransformColumnTypes(Origem,{{"age", Int64.Type}, {"workclass", type text}, {"fnlwgt", Int64.Type}, {"education", type text}, {"education-num", Int64.Type}, {"marital-status", type text}, {"occupation", type text}, {"relationship", type text}, {"race", type text}, {"sex", type text}, {"capital-gain", Int64.Type}, {"capital-loss", Int64.Type}, {"hours-per-week", Int64.Type}, {"native-country", type text}}),
    Output = GetJson(#"Tipo Alterado")
in
    Output

但這又回來了：

[{"age":39,"workclass":"State-gov","fnlwgt":77516,"education":"Bachelors","education-num":13,"marital-status":"Never-married","occupation":"Adm-clerical","relationship":"Not-in-family","race":"White","sex":"Male","capital-gain":2174,"capital-loss":0,"hours-per-week":40,"native-country":"United-States"}]

Answer 1

根據您描述的轉換，特別使用以下 2 個函數可能更有意義：

• Table.ColumnNames
• Table.ToRows

小例子如下：

let
    source = Table.FromRows(
        Json.Document(
            Binary.Decompress(
                Binary.FromText(
                    "HY2xDsIwDET/JTOWGtoSMcIOC0IMVQcrMdSS00huVIm/x2G4e3e64abJ9Wd3cI+KleBTdsshjP5kvGJcSIpuln1vdqedFDKqMiXrl5QhCilHlDaXCrzCGzPL1/pr4UrGG0rD0YfB0JmGZs/V5gT/583N8w8=",
                    BinaryEncoding.Base64
                ),
                Compression.Deflate
            )
        ),
        let 
            _t = ((type nullable text) meta [Serialized.Text = true])
        in 
            type table [age = _t, workclass = _t, fnlwgt = _t, education = _t, #"education-num" = _t, #"marital-status" = _t, occupation = _t, relationship = _t, race = _t, sex = _t, #"capital-gain" = _t, #"capital-loss" = _t, #"hours-per-week" = _t, #"native-country" = _t]
    ),

    CreateJsonPayload = (someTable as table) as binary => Json.FromValue([
        Inputs = [
            input1 = [
                ColumnNames = Table.ColumnNames(someTable),
                Values = Table.ToRows(someTable)
            ]
        ],
        GlobalParameters = []
    ]),
    // If you're doing the POST request via Web.Contents, think you can pass the return value of Json.FromValue
    // directly in as the Content field value.
    // This means you wouldn't need to do Text.FromBinary (at least not for the POST request).
    payload = CreateJsonPayload(source),
    // Below is just for debugging and sanity checking purposes.
    preview = Text.FromBinary(payload)
in
    preview

一些注意事項：

1. 您的示例顯示數字列（如age ）被編碼為字符串（即"0" ）。 如果您希望收件人將它們解碼為數字，您可以調用Table.TransformColumns或Table.TransformColumnTypes來更改類型（視情況而定），然后將轉換后的表傳遞給CreateJsonPayload 。
2. CreateJsonPayload函數接受任何表並返回表示 JSON 的二進制值（實際上只是字節）。 該函數只是一個示例（基於您在問題中提到的預期輸出）。 您顯然可以重構該函數，使其成為適合您的更好的、通用的解決方案。

給我以下內容，我認為這與您的預期輸出相符：