返回 PagedList 时的 EntityCommandExecutionException

编辑：我已经解决了原始问题，但它引起了另一个问题

问题出在这条线上

&& (logLevel == "All" || logLevel == "Error")

"列表"中的 LINQ 查询生成了以下 SQL

SELECT 
0 AS [C1], 
N'guid' AS [C2], 
[Extent1].[ErrorId] AS [ErrorId], 
[Extent1].[TimeUtc] AS [TimeUtc]
FROM [ELMAH_Error] AS [Extent1]
WHERE ([Extent1].[TimeUtc] >= @p__linq__0) AND ([Extent1].[TimeUtc] <= @p__linq__1) AND ((N'All' = @p__linq__2) OR (N'Error' = @p__linq__3)) 

我得到的错误(内部异常="p_linq_2：字符串截断：max=3，len=5，值='错误'(。

(N'All' = @p__linq__2)

当我从 LINQ 查询中删除 logLevel == "All" 时，错误消失了。

所以，我现在的问题是 - 为什么 LINQ/SQL 试图截断p_linq__2？它正在执行比较...为什么需要截断？

---

原始问题

我正在将Elmah和Log4Net与我现有的MVC应用程序集成(遵循本指南 - http://www.codeproject.com/Articles/104112/Log-Reporting-Dashboard-for-ASP-NET-MVC(。 我正在使用 SQL CE 4。 已处理和未处理的错误正在记录到数据库中，我遇到的问题是 UI 查看错误

我收到由此行触发的实体命令执行异常(下面列出了完整的方法(

return new PagedList<LogEvent>(list, pageIndex, pageSize);

• 错误消息 ="执行命令时出错定义。有关详细信息，请参阅内部异常。
• 内部异常 ="p_linq_2 ：字符串截断：max=3，len=5，值='错误'。

据我所知，"列表"填充正常。

产生错误的方法

public IPagedList<LogEvent> GetByDateRangeAndType(int pageIndex, int pageSize, DateTime start, DateTime end, string logProviderName, string logLevel)
    {
        IQueryable<LogEvent> list = null;
        switch (logProviderName)
        {
            case "All":
                foreach (string providerName in logProviders.Keys)
                {
                    IQueryable<LogEvent> logList = GetProvider(providerName).GetByDateRangeAndType(pageIndex, pageSize, start, end, logLevel);
                    list = (list == null) ? logList : list.Union(logList);
                }
                break;
            default:
                list = GetProvider(logProviderName).GetByDateRangeAndType(pageIndex, pageSize, start, end, logLevel);
                break;
        }
        list = list.OrderByDescending(d => d.LogDate);
        return new PagedList<LogEvent>(list, pageIndex, pageSize);
    }

它调用的方法

private ILogReportingRepository GetProvider(string logProviderName)
    {
        string logSourceType = logProviders[logProviderName];
        Type providerType = Type.GetType(logSourceType);
        ILogReportingRepository provider = Activator.CreateInstance(providerType, _context) as ILogReportingRepository;
        return provider;
    }

链接方法

public IQueryable<LogEvent> GetByDateRangeAndType(int pageIndex, int pageSize, DateTime start, DateTime end, string logLevel)
    {
        IQueryable<LogEvent> list = (from a in _context.ELMAH_Error
                                     where a.TimeUtc >= start && a.TimeUtc <= end
                                     && (logLevel == "All" || logLevel == "Error")
                                     select new LogEvent
                                     {
                                         IdType = "guid"
                                       ,
                                         Id = ""
                                       ,
                                         IdAsInteger = 0
                                       ,
                                         IdAsGuid = a.ErrorId
                                       ,
                                         LoggerProviderName = "Elmah"
                                       ,
                                         LogDate = a.TimeUtc
                                       ,
                                         MachineName = a.Host
                                       ,
                                         Message = a.Message
                                       ,
                                         Type = a.Type
                                       ,
                                         Level = "Error"
                                       ,
                                         Source = a.Source,
                                         StackTrace = ""
                                     });
        return list;
    }

堆栈跟踪

[InvalidOperationException： p_linq_2 ： 字符串截断： max=3， len=5， value='Error'。System.Data.SqlServerCe.SqlCeCommand.FillParameterDataBindings(Boolean verifyValue( +1670System.Data.SqlServerCe.SqlCeCommand.ExecuteCommand(CommandBehavior behavior， String method， ResultSetOptions options( +397System.Data.SqlServerCe.SqlCeCommand.ExecuteReader(CommandBehavior behavior( +59System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteReader(CommandBehavior behavior( +342System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteDbDataReader(CommandBehavior behavior( +41System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior( +10System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommand(EntityCommand entityCommand， CommandBehavior behavior( +437

[实体命令执行异常：执行命令定义时出错。有关详细信息，请参阅内部异常。System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommand(EntityCommand entityCommand， CommandBehavior behavior( +507System.Data.Objects.Internal.ObjectQueryExecutionPlan.Execute(ObjectContext context， ObjectParameterCollection parameterValues( +675System.Data.Objects.ObjectQuery 1.GetResults(Nullable 1 forMergeOption( +102System.Data.Objects.ObjectQuery 1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() +30 System.Linq.Enumerable.Single(IEnumerable 1 个源( +100System.Data.Objects.ELinq.ObjectQueryProvider.b__3(IEnumerable 1 sequence) +5 System.Data.Objects.ELinq.ObjectQueryProvider.ExecuteSingle(IEnumerable 1 个查询，表达式查询根( +25System.Data.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute(表达式表达式( +70System.Data.Entity.Internal.Linq.DbQueryProvider.Execute(表达式表达式( +82System.Linq.Queryable.Count(IQueryable 1 source) +233 MvcPaging.PagedList 1..ctor(IQueryable 1 source, Int32 index, Int32 pageSize, Nullable 1 totalCount( +532IDSM。Repository.LogReportingFacade.GetByDateRangeAndType(Int32 pageIndex， Int32 pageSize， DateTime start， DateTime end，

---

&& (logLevel == "All" || logLevel == "Error")

SELECT 
0 AS [C1], 
N'guid' AS [C2], 
[Extent1].[ErrorId] AS [ErrorId], 
[Extent1].[TimeUtc] AS [TimeUtc]
FROM [ELMAH_Error] AS [Extent1]
WHERE ([Extent1].[TimeUtc] >= @p__linq__0) AND ([Extent1].[TimeUtc] <= @p__linq__1) AND ((N'All' = @p__linq__2) OR (N'Error' = @p__linq__3)) 

(N'All' = @p__linq__2)