How to properly query a Json Object with SelectToken-CodePudding

I have a JSON object like in below.

{
  "?xml": {
    "@version": "1.0",
    "@encoding": "UTF-8"
  },
  "?xml-stylesheet": "type=\"text/xsl\" href=\"isokur.xsl\"",
  "Tarih_Date": {
    "@Tarih": "14.10.2022",
    "@Date": "10/14/2022",
    "@Bulten_No": "2022/196",
    "Currency": [
      {
        "@CrossOrder": "0",
        "@Kod": "USD",
        "@CurrencyCode": "USD",
        "Unit": "1",
        "Isim": "ABD DOLARI",
        "CurrencyName": "US DOLLAR",
        "ForexBuying": "18.5596",
        "ForexSelling": "18.5930",
        "BanknoteBuying": "18.5466",
        "BanknoteSelling": "18.6209",
        "CrossRateUSD": null,
        "CrossRateOther": null
      },
      {
        "@CrossOrder": "1",
        "@Kod": "AUD",
        "@CurrencyCode": "AUD",
        "Unit": "1",
        "Isim": "AVUSTRALYA DOLARI",
        "CurrencyName": "AUSTRALIAN DOLLAR",
        "ForexBuying": "11.6732",
        "ForexSelling": "11.7493",
        "BanknoteBuying": "11.6195",
        "BanknoteSelling": "11.8198",
        "CrossRateUSD": "1.5862",
        "CrossRateOther": null
      }
    ]
  }
}

And I want to grab only the this part from it. Where @CurrencyCode == "USD"

[
      {
        "@CrossOrder": "0",
        "@Kod": "USD",
        "@CurrencyCode": "USD",
        "Unit": "1",
        "Isim": "ABD DOLARI",
        "CurrencyName": "US DOLLAR",
        "ForexBuying": "18.5596",
        "ForexSelling": "18.5930",
        "BanknoteBuying": "18.5466",
        "BanknoteSelling": "18.6209",
        "CrossRateUSD": null,
        "CrossRateOther": null
      }
]

For this purpose, I created the code below according to this answer.

string result = JObject.Parse(json)["Tarih_Date"].SelectToken("$.Currency[?(@.@CurrencyCode=='USD')]")["Currency"].ToString();

But I couldn't make it word and I get the exception below. As I understand, my query doesn't find it's way(?) But couldn't understand where it is.

System.NullReferenceException: 'Object reference not set to an instance of an object.'

Anything helps!

CodePudding user response：

You get the exception because there is no property called Currency in the output of SelectToken. You will get the desired output by switching to:

var result = JObject.Parse(json)["Tarih_Date"].SelectToken("$.Currency[?(@.@CurrencyCode == 'USD')]");