这真让我难过。我在数据库中有四个表，不幸的是，设计此表的人没有创建参照约束。因此，没有可用的导航属性。
四个表是：
CiscoPhoneReport
ApplicationSummary
CSQActivityReport
CallDistributionSummary
我们的想法是，对于CiscoPhoneReport中的每个PhoneReportID，有一个ApplicationSummary，三个CSQActivityReport和三个CallDistributionSummary。
我希望输出如下JSON格式：
`[{
"appSummary":{
"startDate":"2015-09-01T00:00:00",
"endDate":"2015-09-30T00:00:00",
"applicationName":"RationalDrugTherapy",
"callsPresented":14504,
"callsAbandoned":1992,
"callsHandled":12512
},
"csqModel":[
{
"startDate":null,
"csqid":"3",
"callsPresented":6271,
"avgQueueTime":"00:00:21",
"callsHandled":0,
"avgAnswerSpeed":"00:00:00",
"avgHandleTime":"00:02:08",
"callsHandledGreaterThan3t":5742,
"callsAbandoned":99,
"avgAbandonTime":"00:02:20",
"maxQueueTime":"00:25:26",
"maxHandleTime":"00:19:33",
"maxAbandonTime":"00:17:50"
},{
"startDate":null,
"csqid":"3",
"callsPresented":6271,
"avgQueueTime":"00:00:21",
"callsHandled":0,
"avgAnswerSpeed":"00:00:00",
"avgHandleTime":"00:02:08",
"callsHandledGreaterThan3t":1728,
"callsAbandoned":99,
"avgAbandonTime":"00:02:20",
"maxQueueTime":"00:25:26",
"maxHandleTime":"00:19:33",
"maxAbandonTime":"00:17:50"
}, {
"startDate":null,
"csqid":"3",
"callsPresented":6271,
"avgQueueTime":"00:00:21",
"callsHandled":0,
"avgAnswerSpeed":"00:00:00",
"avgHandleTime":"00:02:08",
"callsHandledGreaterThan3t":3363,
"callsAbandoned":99,
"avgAbandonTime":"00:02:20",
"maxQueueTime":"00:25:26",
"maxHandleTime":"00:19:33",
"maxAbandonTime":"00:17:50"
}]
}]`
为此，我创建了DTO：
`public class AppSummary
{
public string PhoneReportID { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public string ApplicationName { get; set; }
public int CallsPresented { get; set; }
public int CallsAbandoned { get; set; }
public int CallsHandled { get; set; }
}
`
`public class CSQModel
{
public string StartDate { get; set; }
public string CSQID { get; set; }
public int CallsPresented { get; set; }
public TimeSpan AvgQueueTime { get; set; }
public int CallsHandled { get; set; }
public TimeSpan AvgAnswerSpeed { get; set; }
public TimeSpan AvgHandleTime { get; set; }
public int CallsHandledGreaterThan3t { get; set; }
public int CallsAbandoned { get; set; }
public TimeSpan AvgAbandonTime { get; set; }
public TimeSpan MaxQueueTime { get; set; }
public TimeSpan MaxHandleTime { get; set; }
public TimeSpan MaxAbandonTime { get; set; }
}
`
`public class PhoneReport
{
public AppSummary AppSummary { get; set; }
//Initially, I had it like this
public CSQModel CSQModel { get; set; }
//I renamed the property as LIST to see if I could use it and add data to the list in linq, but I couldn't use the list within select expression in linq.
//public List<CSQModel> CSQModel { get; set; }
}
`
CSQModel类需要来自CSQActivityReport和CallDistributionSummary表的数据。
我能够使用表连接创建一个linq语句，如下所示。
var res = from cpr in db.CiscoPhoneReport
join app in db.ApplicationSummary on cpr.PhoneReportID equals app.PhoneReportID into g1
from appGroup in g1.DefaultIfEmpty()
join csq in db.CSQActivityReport on cpr.PhoneReportID equals csq.PhoneReportID into g2
from csqGroup in g2.DefaultIfEmpty()
join call in db.CallDistributionSummary on cpr.PhoneReportID equals call.PhoneReportID into g3
from callGroup in g3.DefaultIfEmpty()
where cpr.PhoneReportID == phoneReportID
select new PhoneReport
{
AppSummary = new AppSummary
{
StartDate = cpr.StartDate,
EndDate = cpr.EndDate,
ApplicationName = appGroup.ApplicationName,
CallsPresented = appGroup.CallsPresented,
CallsAbandoned = appGroup.CallsAbandoned,
CallsHandled = appGroup.CallsHandled
},
CSQModel = new CSQModel
{
CSQID = csqGroup.CSQID.ToString(),
CallsPresented = csqGroup.CallsPresented,
AvgQueueTime = csqGroup.AvgQueueTime,
AvgHandleTime = csqGroup.AvgHandleTime,
CallsHandledGreaterThan3t = callGroup.CallsHandledGreaterThan3t,
CallsAbandoned = csqGroup.CallsAbandoned,
AvgAbandonTime = csqGroup.AvgAbandonTime,
MaxQueueTime = csqGroup.MaxQueueTime,
MaxHandleTime = csqGroup.MaxHandleTime,
MaxAbandonTime = csqGroup.MaxAbandonTime
}
};
`
我得到的结果是一组包含9行的数据，这是有意义的 - 就像在SQL中的内连接一样。但这不是我想要的。
如何获取上述JSON格式的数据？我根本无法解决这个问题。
答案 0 :(得分：1)
我认为您看到9条记录的部分原因是因为您使用的语法是left outer joins in Linq的语法。
可能有用的是使用子查询以您想要的格式获取所需的数据。
例如
var res = from cpr in db.CiscoPhoneReport
join app in db.ApplicationSummary on cpr.PhoneReportID equals app.PhoneReportID
where cpr.PhoneReportID == phoneReportID
select new PhoneReport
{
AppSummary = new AppSummary
{
// Mappings
},
CSQModel = (from model in db.CSQActivityReport
where model.PhoneReportId == phoneReportID
select new CSQModel
{
// Mappings
}).ToList()
}
你是对的，你需要CSQModels成为某种类型的集合，无论是List还是基本ICollection类型CSQModel。您可以根据需要为CallDistributionSummary编写另一个子查询。
答案 1 :(得分：0)
对于每个主记录，您在2个单独的子表中分别有3条记录。除非您添加更多信息，否则您所做的任何连接都将为您提供9条记录（即使您直接使用T-SQL）。
在SQL中执行此操作的一种方法是将表A中的记录1连接到表B中的记录1，您需要一个索引器来执行此操作。 T-SQL中的一个选项是在每个子表上使用ROW_NUMBER()函数，并在连接中使用该值。但是，ROW_NUMBER()还没有扩展到LINQ。
如果您无法获得重复记录，只需对每个子结果集进行Distinct()调用。然后你可以做两个或三个单独的查询。
注意：您可以将其捆绑到存储过程中的3个结果集中。您可以轻松获取EntityFramework以将每个结果反序列化为您的POCO ..
var objCtx = ((IObjectContextAdapter)ctx).ObjectContext;
using (SqlCommand cmd = ctx.Database.Connection.CreateCommand() as SqlCommand)
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "<your proc here>";
var param = cmd.CreateParameter();
param.ParameterName = "@param1";
param.Value = someValue;
cmd.Parameters.Add(param);
await cmd.Connection.OpenAsync();
using (var reader = await cmd.ExecuteReaderAsync())
{
var results = objCtx.Translate<type1Here>(reader).ToList();
reader.NextResult();
var results2 = objCtx.Translate<type2Here>(reader).ToList();
reader.NextResult();
var results3 = objCtx.Translate<type3Here>(reader).ToList();
reader.NextResult();
}
}
答案 2 :(得分：-1)
您可以序列化您的对象：
DataContractJsonSerializer serializer = new DataContractJsonSerializer(GenericObject.GetType());
MemoryStream ms = new MemoryStream();
serializer.WriteObject(ms, GenericObject);
string json = Encoding.UTF8.GetString(ms.ToArray());
ms.Close();
return json;