C# 从SQL Server查询C中的JSON

我使用Audit.Net来审计我的ASP.Net Razor应用程序，结果以JSON格式存储在SQL Server数据库中。该表的名称称为AuditTrail，JSON结果存储在名为JsonData的列中。典型的JSON输出如下所示：

{
    "EventType": "GET /Account/Menu",
    "Environment": {
        "UserName": "xxx",
        "MachineName": "xxx-MacBook-Pro",
        "DomainName": "xxx-MacBook-Pro",
        "CallingMethodName": "xxx.Areas.Identity.Pages.Account.MenuModel.OnGet()",
        "AssemblyName": "xxx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null",
        "Culture": ""
    },
    "StartDate": "2020-12-10T14:44:47.067556Z",
    "EndDate": "2020-12-10T14:44:47.067788Z",
    "Duration": 0,
    "Action": {
        "TraceId": "xxxx",
        "HttpMethod": "GET",
        "ControllerName": "Identity",
        "ActionName": "/Account/Menu",
        "ViewPath": "/Account/Menu",
        "ActionParameters": {},
        "RequestBody": {},
        "ResponseBody": {
            "Type": "PageResult"
        },
        "UserName": "xxx@gmail.com",
        "RequestUrl": "https://localhost:5001/Identity/Account/Menu",
        "IpAddress": "::1",
        "ResponseStatusCode": 200
    }
}

我的问题是如何从JSON输出中选择一个特定的参数，即Action.UserName，而不必输出整个JSON输出，这就是它当前所做的，然后将其传递给视图。到目前为止，我所做的是将JSON输出表示为一个类，然后连接到数据库，但它不起作用

    public class Action
    {
        public string TraceId { get; set; }
        public string HttpMethod { get; set; }
        public string ControllerName { get; set; }
        public string ActionName { get; set; }
        public string ViewPath { get; set; }
        public string UserName { get; set; }
        public string RequestUrl { get; set; }
        public string IpAddress { get; set; }
        public int ResponseStatusCode { get; set; }
    }

    public class Audits
    {
        public List<Action> Actions { get; set; }
    }

         string connectionString = "Data Source=localhost;User ID=sa;Password=xxx;initial 
         catalog=xxx.db;integrated security=false;";

        public string UserName { get; set; }
        public string IpAddress { get; set; }
        public string HttpMethod { get; set; }

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            string query = "SELECT JsonData FROM AuditTrail";
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                connection.Open();
                List<AuditLog> auditLogs1 = new List<AuditLog>();
                var reader = command.ExecuteReader();
                if (reader.HasRows)
                {
                    while (reader.Read())
                    {
                        AuditLog audit1 = new AuditLog();
                        audit1.User = reader["JsonData"].ToString();
                        auditLogs1.Add(audit1);
                    }
                    connection.Close();
                }
                var JsonResult = JsonConvert.SerializeObject(auditLogs1);
                var JsonResult1 = JsonConvert.DeserializeObject<Audits>(JsonResult);

                foreach (var x in JsonResult1.Actions)
                {
                    UserName = x.UserName;
                    HttpMethod = x.HttpMethod;
                    IpAddress = x.IpAddress;
                }
           }

---

好的，您只能通过以下方式从JSON获取操作键：

            using (SqlCommand command = new SqlCommand(query, connection))
            {
                connection.Open();
                List<AuditLog> auditLogs1 = new List<AuditLog>();
                var reader = command.ExecuteReader();
                if (reader.HasRows)
                {
                    while (reader.Read())
                    {
                        AuditLog audit1 = new AuditLog();
                        audit1.User = reader["JsonData"].ToString();
                        auditLogs1.Add(audit1);
                    }
                    connection.Close();
                }

                var root = JObject.Parse(auditLogs1);
                var audit = new Audits() { Actions = new List<Action>() };
                var action = root["Action"].ToObject<Action>();
                
                audit.Actions.Add(action);

                foreach (var x in audit.Actions)
                {
                    UserName = x.UserName;
                    HttpMethod = x.HttpMethod;
                    IpAddress = x.IpAddress;
                }
           }

---

有了它，您可以了解您在Sql Server 2016和更新版本中可能正在做什么，您可以通过更新查询来简化这一过程：

SELECT
    JSON_VALUE(JsonData, '$.Action.UserName') as UserName
   ,JSON_VALUE(JsonData, '$.Action.HttpMethod') as HttpMethod
   ,JSON_VALUE(JsonData, '$.Action.IpAddress') as IpAddress
FROM
    [dbo].[AuditTrail]

将其应用到您的代码中，您将得到：

List<AuditLog> logs = new List<AuditLog>();
using (SqlConnection connection = new SqlConnection(connectionString))
{
    string query = @"SELECT
        JSON_VALUE(JsonData, '$.Action.UserName') as UserName
       ,JSON_VALUE(JsonData, '$.Action.HttpMethod') as HttpMethod
       ,JSON_VALUE(JsonData, '$.Action.IpAddress') as IpAddress
      FROM
        [dbo].[AuditTrail]";

    using (SqlCommand command = new SqlCommand(query, connection))
    {
        connection.Open();
        var reader = command.ExecuteReader();
        if (reader.HasRows)
        {
            while (reader.Read())
            {
                logs.Add(new AuditLog
                {
                    UserName = reader["UserName"].ToString(),
                    HttpMethod = reader["HttpMethod"].ToString(),
                    IpAddress = reader["IpAddress"].ToString()
                });
            }
        }
    }
}

---

你现在得到了什么结果？你的日常工作中有没有出现错误？预期结果是什么？@MestreDosMagros目前没有显示任何内容，也没有出现错误。预期结果是UserName、HttpMethod和IpAddress应该显示JSON输出中当前显示的值？较新版本的MSSQL具有内置的JSON函数，MSSQL将为您查询JSON，因此您可以返回所需的字符串，而不是提取整个JsonDatadown@McAden我正在运行SQL Server 2019非常感谢，我对SQL仍然很陌生。本季的致意。在SQL server 2014中是否有这样做的方法？感谢您没有使用这种方法，您需要将其作为字符串提取并解析。