LINQ to JSON - 查询对象或数组

Question

我正在尝试获取 SEDOL 和 ADP 值的列表。下面是我的 json 文字：

{
    "DataFeed" : {
        "@FeedName" : "AdminData",
        "Issuer" : [{
                "id" : "1528",
                "name" : "ZYZ.A a Test Company",
                "clientCode" : "ZYZ.A",
                "securities" : {
                    "Security" : {
                        "id" : "1537",
                        "sedol" : "SEDOL111",
                        "coverage" : {
                            "Coverage" : [{
                                    "analyst" : {
                                        "@id" : "164",
                                        "@clientCode" : "SJ",
                                        "@firstName" : "Steve",
                                        "@lastName" : "Jobs",
                                        "@rank" : "1"
                                    }
                                }, {
                                    "analyst" : {
                                        "@id" : "261",
                                        "@clientCode" : "BG",
                                        "@firstName" : "Bill",
                                        "@lastName" : "Gates",
                                        "@rank" : "2"
                                    }
                                }
                            ]
                        },
                        "customFields" : {
                            "customField" : [{
                                    "@name" : "ADP Security Code",
                                    "@type" : "Textbox",
                                    "values" : {
                                        "value" : "ADPSC1111"
                                    }
                                }, {
                                    "@name" : "Top 10 - Select one or many",
                                    "@type" : "Dropdown, multiple choice",
                                    "values" : {
                                        "value" : ["Large Cap", "Cdn Small Cap", "Income"]
                                    }
                                }
                            ]
                        }
                    }
                }
            }, {
                "id" : "1519",
                "name" : "ZVV Test",
                "clientCode" : "ZVV=US",
                "securities" : {
                    "Security" : [{
                            "id" : "1522",
                            "sedol" : "SEDOL112",
                            "coverage" : {
                                "Coverage" : {
                                    "analyst" : {
                                        "@id" : "79",
                                        "@clientCode" : "MJ",
                                        "@firstName" : "Michael",
                                        "@lastName" : "Jordan",
                                        "@rank" : "1"
                                    }
                                }
                            },
                            "customFields" : {
                                "customField" : [{
                                        "@name" : "ADP Security Code",
                                        "@type" : "Textbox",
                                        "values" : {
                                            "value" : "ADPS1133"
                                        }
                                    }, {
                                        "@name" : "Top 10 - Select one or many",
                                        "@type" : "Dropdown, multiple choice",
                                        "values" : {
                                            "value" : ["Large Cap", "Cdn Small Cap", "Income"]
                                        }
                                    }
                                ]
                            }
                        }, {
                            "id" : "1542",
                            "sedol" : "SEDOL112",
                            "customFields" : {
                                "customField" : [{
                                        "@name" : "ADP Security Code",
                                        "@type" : "Textbox",
                                        "values" : {
                                            "value" : "ADPS1133"
                                        }
                                    }, {
                                        "@name" : "Top 10 - Select one or many",
                                        "@type" : "Dropdown, multiple choice",
                                        "values" : {
                                            "value" : ["Large Cap", "Cdn Small Cap", "Income"]
                                        }
                                    }
                                ]
                            }
                        }
                    ]
                }
            }
        ]
    }
}

这是我目前拥有的代码：

var compInfo = feed["DataFeed"]["Issuer"]
.Select(p => new {  
    Id = p["id"],
    CompName = p["name"],
    SEDOL = p["securities"]["Security"].OfType<JArray>() ? 
        p["securities"]["Security"][0]["sedol"] : 
        p["securities"]["Security"]["sedol"]
    ADP = p["securities"]["Security"].OfType<JArray>() ? 
        p["securities"]["Security"][0]["customFields"]["customField"][0]["values"]["value"] : 
        p["securities"]["Security"]["customFields"]["customField"][0]["values"]["value"]
});

我得到的错误是：

Accessed JArray values with invalid key value: "sedol". Int32 array index expected

我想我真的快要解决这个问题了。我应该怎么做才能修复代码？如果有其他方法可以获得 SEDOL 和 ADP value，请告诉我？

[UPDATE1] 我已经开始使用动态 ExpandoObject。这是我到目前为止使用的代码：

dynamic obj = JsonConvert.DeserializeObject<ExpandoObject>(json, new ExpandoObjectConverter());
foreach (dynamic element in obj)
{
    Console.WriteLine(element.DataFeed.Issuer[0].id);
    Console.WriteLine(element.DataFeed.Issuer[0].securities.Security.sedol);
    Console.ReadLine();
}

但我现在收到错误 'ExpandoObject' does not contain a definition for 'DataFeed' and no extension method 'DataFeed' accepting a first argument of type 'ExpandoObject' could be found。 注意： 我了解此 json 文本格式错误。一个实例有一个数组，另一个是一个对象。我希望代码足够敏捷以处理这两个实例。

[UPDATE2] 感谢@dbc 到目前为止帮助我编写代码。我更新了上面的 json 文本以与我当前的环境非常匹配。我现在可以获得 SEDOL 和 ADP 代码。但是，当我试图获得第一位分析师时，我的代码仅适用于对象并为作为数组一部分的分析师生成空值。这是我当前的代码：

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
           let security = issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf()).FirstOrDefault()
           where security != null
           select new
           {
               Id = (string)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
               CompName = (string)issuer["name"],
               SEDOL = (string)security["sedol"],
               ADP = security["customFields"]
                .DescendantsAndSelf()
                .OfType<JObject>()
                .Where(o => (string)o["@name"] == "ADP Security Code")
                .Select(o => (string)o.SelectToken("values.value"))
                .FirstOrDefault(),
              Analyst = security["coverage"]
                .DescendantsAndSelf()
                .OfType<JObject>()
                .Select(jo => (string)jo.SelectToken("Coverage.analyst.@lastName"))
                .FirstOrDefault(),
           };

我需要更改什么才能始终 select 第一分析师？

Answer 1

使用newtonsoft.json

dynamic obj = JsonConvert.DeserializeObject<ExpandoObject>(json);

我前面没有 ide，但值应该是：

obj.DataFeed.Issuer[0].securities.Security.sedol

Answer 2

另请注意，您的 JSON 格式不正确。

创建的代理 class 无法确定 Security 的类型，因为在一个实例中它是一个数组，而在另一个实例中它是一个简单的对象。

Original answer:

我使用 json2csharp 来帮助我获得一些 classes，现在我可以使用以下类型：

        var obj = JsonConvert.DeserializeObject<RootObject>(json);
        var result = from a in obj.DataFeed.Issuer
                     select new
                     {
                         Sedol = a.securities.Security.sedol,
                         Name = a.name
                     };

类:

     public class Values
    {
        public object value { get; set; }
    }

    public class CustomField
    {
        public string name { get; set; }
        public string type { get; set; }
        public Values values { get; set; }
    }

    public class CustomFields
    {
        public List<CustomField> customField { get; set; }
    }

    public class Security
    {
        public string id { get; set; }
        public string sedol { get; set; }
        public CustomFields customFields { get; set; }
    }

    public class Securities
    {
        public Security Security { get; set; }
    }
    public class Issuer
    {
        public string id { get; set; }
        public string name { get; set; }
        public string clientCode { get; set; }
        public Securities securities { get; set; }
    }

    public class DataFeed
    {
        public string FeedName { get; set; }
        public List<Issuer> Issuer { get; set; }
    }

    public class RootObject
    {
        public DataFeed DataFeed { get; set; }
    }

Answer 3

如果您想要所有 SEDOL 和 ADP 值以及每个值的相关发行者 ID 和 CompName，您可以执行以下操作：

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
               from security in issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf())
               select new
               {
                   Id = (long)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
                   CompName = (string)issuer["name"],
                   SEDOL = (string)security["sedol"],
                   ADP = security["customFields"]
                    .DescendantsAndSelf()
                    .OfType<JObject>()
                    .Where(o => (string)o["@name"] == "ADP Security Code")
                    .Select(o => (string)o.SelectToken("values.value"))
                    .FirstOrDefault(),
               };

使用扩展方法：

public static class JsonExtensions
{
    public static IEnumerable<JToken> DescendantsAndSelf(this JToken node)
    {
        if (node == null)
            return Enumerable.Empty<JToken>();
        var container = node as JContainer;
        if (container != null)
            return container.DescendantsAndSelf();
        else
            return new[] { node };
    }

    public static IEnumerable<JObject> ObjectsOrSelf(this JToken root)
    {
        if (root is JObject)
            yield return (JObject)root;
        else if (root is JContainer)
            foreach (var item in ((JContainer)root).Children())
                foreach (var child in item.ObjectsOrSelf())
                    yield return child;
        else
            yield break;
    }
}

然后

Console.WriteLine(JsonConvert.SerializeObject(compInfo, Formatting.Indented));

产生：

[
  {
    "Id": 1528,
    "CompName": "ZYZ.A a Test Company",
    "SEDOL": "SEDOL111",
    "ADP": "ADPSC1111"
  },
  {
    "Id": 1519,
    "CompName": "ZVV Test",
    "SEDOL": "SEDOL112",
    "ADP": "ADPS1133"
  },
  {
    "Id": 1519,
    "CompName": "ZVV Test",
    "SEDOL": "SEDOL112",
    "ADP": "ADPS1133"
  }
]

但是，在您到目前为止编写的查询中，您似乎试图 return 仅为每个发行人的 first SEDOL 和 ADP。如果那真的是你想要的，请执行：

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
               let security = issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf()).FirstOrDefault()
               where security != null
               select new
               {
                   Id = (long)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
                   CompName = (string)issuer["name"],
                   SEDOL = (string)security["sedol"],
                   ADP = security["customFields"]
                    .DescendantsAndSelf()
                    .OfType<JObject>()
                    .Where(o => (string)o["@name"] == "ADP Security Code")
                    .Select(o => (string)o.SelectToken("values.value"))
                    .FirstOrDefault(),
               };

这导致：

[
  {
    "Id": 1528,
    "CompName": "ZYZ.A a Test Company",
    "SEDOL": "SEDOL111",
    "ADP": "ADPSC1111"
  },
  {
    "Id": 1519,
    "CompName": "ZVV Test",
    "SEDOL": "SEDOL112",
    "ADP": "ADPS1133"
  }
]

顺便说一句，因为你的 JSON 是多态的（属性有时是对象数组，有时只是对象）我不认为反序列化到 class 层次结构或 ExpandoObject 会更容易。

更新

根据您更新后的 JSON，您可以使用 SelectTokens() with the JSONPath recursive search operator .. 查找第一位分析师的姓氏，其中递归搜索运算符处理分析师可能包含也可能不包含在数组中的事实:

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
               let security = issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf()).FirstOrDefault()
               where security != null
               select new
               {
                   Id = (string)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
                   CompName = (string)issuer["name"],
                   SEDOL = (string)security["sedol"],
                   ADP = (string)security["customFields"]
                    .DescendantsAndSelf()
                    .OfType<JObject>()
                    .Where(o => (string)o["@name"] == "ADP Security Code")
                    .Select(o => o.SelectToken("values.value"))
                    .FirstOrDefault(),
                   Analyst = (string)security.SelectTokens("coverage.Coverage..analyst.@lastName").FirstOrDefault(),
               };

LINQ to JSON - 查询对象或数组

LINQ to JSON - Query for object or an array

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