SharePoint, List.Items and List.GetItems (Query) and Linq

Question

Following the recommendations, I am trying to use List.GetItems (Query) to retrieve my original subset of data, and not the entire contents of a list through List.Items. However, while List.Items.Cast () leads to a useful IEnumerable for Linq, List.GetItems (Query) .Cast () does not.

Work code:

IEnumerable<SPListItem> results = SPContext.Current.Web.Lists[ListName].Items.Cast<SPListItem>().Where(item => item["Date"] != null).Where(item => DateTime.Parse(item["Date"].ToString()) >= StartDate).Where(item => DateTime.Parse(item["Date"].ToString()) <= EndDate); MessageLine = results.Count().ToString(); 

Inoperative code:

 string SPStartDate = SPUtility.CreateISO8601DateTimeFromSystemDateTime(this.StartDate); string SPEndDate = SPUtility.CreateISO8601DateTimeFromSystemDateTime(this.EndDate); SPQuery MyQuery = new SPQuery(); MyQuery.Query = "<Where><And><And><Geq><FieldRef Name='Date'/><Value Type='DateTime'>" + SPStartDate + "</Value></Geq><Leq><FieldRef Name='Date'/><Value Type='DateTime'>" + SPEndDate + "</Value></Leq></And></Where>"; IEnumerable<SPListItem> results = SPContext.Current.Web.Lists[ListName].GetItems(MyQuery).Cast<SPListItem>(); MessageLine = results.Count().ToString(); 

The List.GetItems (Query) .Cast () method throws the following exception on the .Count () line:

Microsoft.SharePoint.SPException: This action cannot be completed. please try again. ---> System.Runtime.InteropServices.COMException (0x80004005): This action cannot be completed. Please try again. in Microsoft.SharePoint.Library.SPRequestInternalClass.GetListItemDataWithCallback (String bstrUrl, String bstrListName, String bstrViewName, String bstrViewXml, SAFEARRAYFLAGS fSafeArrayFlags, ISP2DSafeArrayWriter pSACallback, ISPDataCallback pPagingCallback, ISPDataCallback pSchemaCallback) at Microsoft.SharePoint.Library.SPRequest.GetListItemDataWithCallback (String bstrUrl, String bstrListName, String bstrViewName, String bstrViewXml, SAFEARRAYFLAGS fSafeArrayFlags, ISP2DSafeArrayWriter pSACallback, ISPDataCallback pPagingCallback, ISPDataCallback pSchemaCallback) --- End of inner exception stack trace --- in Microsoft.SharePoint.Library.SPRequest.GetListItemDataWithCallback (String bstrUrl, String bstrListName, String bstrViewName , String bstrViewXml, SAFEARRAYFLAGS fSafeArrayFlags, ISP2DSafeArrayWriter pSACallback, ISPDataCallback pPagingCallback, ISPDataCallback pSchemaCallback) with Microsoft.SharePoint.SPListItemCollection .EnsureListItemsData () in Microsoft.SharePoint.SPListItemCollection.Undirty () in Microsoft.SharePoint.SPBaseCollection.System.Collections.IEnumerable.GetEnumerator () in System.Linq.Enumerable.d__aa 1.MoveNext() at System.Linq.Enumerable.Count[TSource](IEnumerable 1 source) in Test.GetTransactionsInPeriod () at Test.CreateChildControls ()

Can anyone suggest something?

Answer 1

From the error message, it seems that CAML Query is erroneous. You can run it using the U2U CAML Query Builder for double validation. The error message is called by SharePoint before the requests. Looking at it, I think you have an extra <And> at the beginning ( <Where><And><And> )

By the way: Do not use SPWeb.Lists [Name]. This will load each list into SPWeb (including metadata), which is quite resource intensive. One of the methods SPWeb.GetList or SPWeb.Lists.GetList is better .