Ошибка веб-приложения: последовательность содержит более одного элемента

У меня есть веб-приложение, которое работало нормально, но больше не работает. Он работает даже на моем компьютере разработчика (подключенном к локальной базе данных), но не в производственной среде. Итак, на своем компьютере разработки я меняю строку подключения, чтобы попасть в производственную базу данных, и получаю сообщение об ошибке: последовательность содержит более одного элемента.

Я считаю, что это как-то связано с базой данных, но я не знаю, как понять, что это такое, в ней почти тысяча строк данных.

Ниже приведен оператор linq, который получает данные. Есть идеи, как я могу это исправить?

Заранее спасибо

protected void lnqItems_Selecting(object sender, LinqDataSourceSelectEventArgs e)
{
    DocksideValidationDataContext db = new DocksideValidationDataContext();

    DateTime startDate = (radStartDate.SelectedDate.HasValue)
        ? radStartDate.SelectedDate.Value
        : DateTime.Parse("1/1/1900");
    DateTime endDate = (radEndDate.SelectedDate.HasValue)
        ? radEndDate.SelectedDate.Value
        : DateTime.Parse("1/1/2500");
    int prevalNum = (txtSummaryFormNumber.Text.Trim() == "")
        ? -1
        : Convert.ToInt32(txtSummaryFormNumber.Text.Trim());

    e.Result = (from x in db.SummaryForms
                where (x.SummaryFormId == prevalNum
                    || (prevalNum == -1)
                    && (x.SampleDate >= startDate.Date)
                    && (x.SampleDate <= endDate.Date)
                    && (x.StateId == Convert.ToInt32(ddlState.SelectedValue)))
                orderby (x.SampleDate) descending
                select x).AsEnumerable()
                         .Select(x => new
                         {
                             x.SummaryFormId,
                             x.SampleDate,
                             DockName = x.Dock.Code + " " + x.Dock.Name,
                             Status = GetStatus(x),
                             Color = GetStatusColor(GetStatus(x))
                         })
                        .Where(x => ((prevalNum != -1
                            || cboFilter.Text == "All")
                            || (x.Status == cboFilter.Text)));
}

Нет, это пришло мне в голову, но я не думал, что это будет полезно. Вот он:

System.InvalidOperationException: Sequence contains more than one element

Generated: Sat, 24 Sep 2011 15:57:41 GMT

System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: Sequence contains more than one element
   at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source)
   at System.Data.Linq.EntityRef`1.get_Entity()
   at Secure_SummaryForms.<GetStatus>b__4(SummaryFormVessel z)
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source)
   at Secure_SummaryForms.GetStatus(SummaryForm x)
   at Secure_SummaryForms.<lnqItems_Selecting>b__0(SummaryForm x)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner)
   at System.RuntimeMethodHandle.InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeType typeOwner)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Web.UI.WebControls.QueryableDataSourceHelper.ToList(IQueryable query, Type dataObjectType)
   at System.Web.UI.WebControls.LinqDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments)
   at System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback)
   at System.Web.UI.WebControls.DataBoundControl.PerformSelect()
   at System.Web.UI.WebControls.BaseDataBoundControl.DataBind()
   at System.Web.UI.WebControls.GridView.DataBind()
   at System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound()
   at System.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls()
   at System.Web.UI.Control.EnsureChildControls()
   at System.Web.UI.WebControls.GridView.get_Rows()
   at Secure_SummaryForms.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.secure_summaryforms_aspx.ProcessRequest(HttpContext context)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)


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Name    Value
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ALL_RAW Connection: keep-alive Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Accept-Encoding: gzip, deflate Accept-Language: en-us,en;q=0.5 Cookie: ASP.NET_SessionId=yka231rdr1r3yqv0nmbhz1nh; .POWERBASECOOKIE=5FC2CF98E578B444ACA6B75A382EAEF31EFC781DA11AF7884B360A82E544539BEC5E5BB62DD012A1D6E7005869FFF8A205D632FB724AB01EFDBED78A9A035C76B22250F8FF0BCC3AD9AB56C4EEC44C05159110DF95A6344888CB3300B642E312F3B152475CD4FA631C0000699763AE173978375D598154CE85AEF83C81E1FAF82842DF48F1D9AC97872F09FFCA33B22B; .ASPXROLES=IS-YIxYt7iXk72HXdLNE18SBwgsEd2wo3D4GfRI72jYdSmmLhUxfzBMMpFYXg5CjiowldcwSKolBjaP8jrMUgh5-rQWjQhUTY02VS3IhD5Xcav_B-d-MiaumYD-0JMWFR9-1xcP2eHQXLpnZlXzcZXhwh6G2mEDVoNZGls8MNK8bAVlo2WuTqReMmk1GTyu5duoZzh_fCs1S6AZuhWY9bwdi28kA_lfoyp4SCm2zLgNddjhbsLmgN5oopdPo9-oONS7Z5br51qYu5sS9vq-hm_TbHhHL_W7XbIKo3pJccZ1-VXkLbtIAiS_hSccjFmk1f3ttWhUnmULJVQaNNepOHofbivSEQvhQQxX-f5hpGI4K-9FqcJ-kFAjw93CrnZ2rtu6n8i3tblPEDQeAbd1JkSJjmKGpSH_4PVh1MsXNDZwSSnbBHqTaO9iKiVAvUWvANLbBxmOc3w0SfP4DUbLtl3YZVCbG_JWr5s0f5Is8scr7Nc-AxK2HEzjNVber1EofJK48eLaVJPyvm-858Yhtp5XgqMeJQUwh5l9LYeZNbc8kqxPG7kOl0Zq7q8407I230 Host: docksidevalidation.org Referer: http://docksidevalidation.org/secure/default.aspx User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0.2) Gecko/20100101 Firefox/6.0.2
APPL_MD_PATH    /LM/W3SVC/1154673598/Root
APPL_PHYSICAL_PATH  C:\Inetpub\Websites\DocksideValidation\Website\
AUTH_TYPE   Forms
AUTH_USER   admin
AUTH_PASSWORD    
LOGON_USER   
REMOTE_USER admin
CERT_COOKIE  
CERT_FLAGS   
CERT_ISSUER  
CERT_KEYSIZE     
CERT_SECRETKEYSIZE   
CERT_SERIALNUMBER    
CERT_SERVER_ISSUER   
CERT_SERVER_SUBJECT  
CERT_SUBJECT     
CONTENT_LENGTH  0
CONTENT_TYPE     
GATEWAY_INTERFACE   CGI/1.1
HTTPS   off
HTTPS_KEYSIZE    
HTTPS_SECRETKEYSIZE  
HTTPS_SERVER_ISSUER  
HTTPS_SERVER_SUBJECT     
INSTANCE_ID 1154673598
INSTANCE_META_PATH  /LM/W3SVC/1154673598
LOCAL_ADDR  192.168.1.131
PATH_INFO   /secure/SummaryForms.aspx
PATH_TRANSLATED C:\Inetpub\Websites\DocksideValidation\Website\secure\SummaryForms.aspx
QUERY_STRING     
REMOTE_ADDR 66.186.243.74
REMOTE_HOST 66.186.243.74
REMOTE_PORT 50339
REQUEST_METHOD  GET
SCRIPT_NAME /secure/SummaryForms.aspx
SERVER_NAME docksidevalidation.org
SERVER_PORT 80
SERVER_PORT_SECURE  0
SERVER_PROTOCOL HTTP/1.1
SERVER_SOFTWARE Microsoft-IIS/6.0
URL /secure/SummaryForms.aspx
HTTP_CONNECTION keep-alive
HTTP_ACCEPT text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
HTTP_ACCEPT_CHARSET ISO-8859-1,utf-8;q=0.7,*;q=0.7
HTTP_ACCEPT_ENCODING    gzip, deflate
HTTP_ACCEPT_LANGUAGE    en-us,en;q=0.5
HTTP_COOKIE ASP.NET_SessionId=yka231rdr1r3yqv0nmbhz1nh; .POWERBASECOOKIE=5FC2CF98E578B444ACA6B75A382EAEF31EFC781DA11AF7884B360A82E544539BEC5E5BB62DD012A1D6E7005869FFF8A205D632FB724AB01EFDBED78A9A035C76B22250F8FF0BCC3AD9AB56C4EEC44C05159110DF95A6344888CB3300B642E312F3B152475CD4FA631C0000699763AE173978375D598154CE85AEF83C81E1FAF82842DF48F1D9AC97872F09FFCA33B22B; .ASPXROLES=IS-YIxYt7iXk72HXdLNE18SBwgsEd2wo3D4GfRI72jYdSmmLhUxfzBMMpFYXg5CjiowldcwSKolBjaP8jrMUgh5-rQWjQhUTY02VS3IhD5Xcav_B-d-MiaumYD-0JMWFR9-1xcP2eHQXLpnZlXzcZXhwh6G2mEDVoNZGls8MNK8bAVlo2WuTqReMmk1GTyu5duoZzh_fCs1S6AZuhWY9bwdi28kA_lfoyp4SCm2zLgNddjhbsLmgN5oopdPo9-oONS7Z5br51qYu5sS9vq-hm_TbHhHL_W7XbIKo3pJccZ1-VXkLbtIAiS_hSccjFmk1f3ttWhUnmULJVQaNNepOHofbivSEQvhQQxX-f5hpGI4K-9FqcJ-kFAjw93CrnZ2rtu6n8i3tblPEDQeAbd1JkSJjmKGpSH_4PVh1MsXNDZwSSnbBHqTaO9iKiVAvUWvANLbBxmOc3w0SfP4DUbLtl3YZVCbG_JWr5s0f5Is8scr7Nc-AxK2HEzjNVber1EofJK48eLaVJPyvm-858Yhtp5XgqMeJQUwh5l9LYeZNbc8kqxPG7kOl0Zq7q8407I230
HTTP_HOST   docksidevalidation.org
HTTP_REFERER    http://docksidevalidation.org/secure/default.aspx
HTTP_USER_AGENT Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0.2) Gecko/20100101 Firefox/6.0.2

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