Databind r.a.d.grid

[Hessner]

IObjectScope os = (IObjectScope)Context.Items["ObjectScopeProvider"];
            IQueryable result = from x in os.Extent<UserRole>()
                                where x.PortalID == 1
                                select new { x.User.UserID, x.User.Email, x.User.FuldeNavn, x.Medlemsnummer, x.Role.RoleName, x.User.HuskLogon};

RadGrid1.DataSource = result;

This code will produce a runtime error:

"from 'System.Int32' til 'System.Nullable`1[[System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]'."

I have traced it to the field(see above): x.User.HuskLogon.

This field have the type: int?

If I change it to: int, no error will happen!

I am not sure if r.a.d.grid causing the trouble or it is OpenAccess.

Help, anyone?

[Dimitar Kapitanov]

Hello Hessner,
Can you show us the stack trace?

Best wishes,
Dimitar Kapitanov
the Telerik team

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[Hessner]

Here are the trace:

[InvalidCastException: Ugyldig ændring fra 'System.Int32' til 'System.Nullable`1[[System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]'.]
   System.Convert.DefaultToType(IConvertible value, Type targetType, IFormatProvider provider) +7565416
   System.Int32.System.IConvertible.ToType(Type type, IFormatProvider provider) +36
   System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider) +7597264
   Telerik.OpenAccess.Query.TypedEnumerator`1.Translated(Object c) +865
   Telerik.OpenAccess.Query.TypedEnumerator`1.System.Collections.Generic.IEnumerator<T>.get_Current() +220
   Telerik.OpenAccess.Query.TypedEnumerator`1.System.Collections.IEnumerator.get_Current() +102
   Telerik.Web.UI.GridResolveEnumerable.GetCollectionItemType(Boolean noItemsInEnumerator, Type& itemType, Object& firstObject) +249
   Telerik.Web.UI.GridResolveEnumerable.ParseProperties() +90
   Telerik.Web.UI.GridResolveEnumerable.Initialize() +13
   Telerik.Web.UI.GridResolveEnumerable.EnsureInitialized() +20
   Telerik.Web.UI.GridEnumerableFromDataView..ctor(GridTableView owner, IEnumerable enumerable, Boolean CaseSensitive, Boolean autoGenerateColumns, GridColumnCollection presentColumns, String[] additionalField, Boolean retrieveAllFields) +158
   Telerik.Web.UI.GridDataSourceHelper.CreateGridEnumerable(GridTableView owner, IEnumerable enumerable, Boolean caseSensitive, Boolean autoGenerateColumns, GridColumnCollection presentColumns, String[] additionalField, Boolean retrieveAllFields) +129
   Telerik.Web.UI.GridDataSourceHelper.GetResolvedDataSource(GridTableView owner, Object dataSource, String dataMember, Boolean caseSensitive, Boolean autoGenerateColumns, GridColumnCollection presentColumns, String[] additionalField, Boolean retrieveAllFields) +383
   Telerik.Web.UI.GridTableView.get_ResolvedDataSource() +140
   Telerik.Web.UI.GridTableView.CreateChildControls(IEnumerable dataSource, Boolean useDataSource) +33
   System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding(IEnumerable data) +57
   System.Web.UI.WebControls.DataBoundControl.OnDataSourceViewSelectCallback(IEnumerable data) +114
   System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +31
   System.Web.UI.WebControls.DataBoundControl.PerformSelect() +142
   Telerik.Web.UI.GridTableView.PerformSelect() +4
   System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +73
   Telerik.Web.UI.GridTableView.DataBind() +238
   Telerik.Web.UI.RadGrid.DataBind() +80
   Telerik.Web.UI.RadGrid.AutoDataBind(GridRebindReason rebindReason) +2122
   Telerik.Web.UI.RadGrid.OnLoad(EventArgs e) +121
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Control.LoadRecursive() +141
   System.Web.UI.Control.LoadRecursive() +141
   System.Web.UI.Control.LoadRecursive() +141
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

[Hessner]

Should I open a support ticket regarding this issue?

[Thomas]

Hi Bo Hessner,

thanks for reporting this issue to us. It seems as if the problems exists only for nullable type fields that are in a new structure. OpenAccess gets a value but the called .Net framework method is not able to convert to the nullable type.
I will fix this and the next version will contain the necessary changes.
You Telerik points have been updated.

Best wishes,
Thomas
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Hessner]

1. When will next release be?
2. Can you supply a work around?

[Thomas]

Hello Bo Hessner,

I cannot say yet when the next version will come up, I hope it is not that far away. I will ask my collegue for more information.
Currently, there is two workaround,s and that is not to
(a) use a new anonymous type (no projection)
OR
(b) not to use a nullable field in the projection.

Hope this helps,
Thomas
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Hessner]

I will replace OpenAcces in this query,- do you have any more information regarding the next fix-date?

[Jan Blessenohl]

Hi Hessner,
We wil try to bring out a next patch end of next week.

Greetings,
Jan Blessenohl
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Check out the tips for optimizing your support resource searches.

[Hessner]

Any chance for a patch this weekend?

[Dimitar Kapitanov]

Hi Hessner,
Due to some problems found during the test phase, the SP release is scheduled for tomorrow.

Best wishes,
Dimitar Kapitanov
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Check out the tips for optimizing your support resource searches.

[Sathish]

Hi,

Just an off the topic question, when you write a query like (the one you showed in your example)

IObjectScope os = (IObjectScope)Context.Items["ObjectScopeProvider"];

IQueryable result = from x in os.Extent<UserRole>()

where x.PortalID == 1

select new { x.User.UserID, x.User.Email, x.User.FuldeNavn, x.Medlemsnummer, x.Role.RoleName, x.User.HuskLogon};

How does it actually work? The architecture behind it. Does it download all the data from UserRole table (from db) and then run the LINQ to filter the results? OR does it actually only retrieve data that matched the criteria from the DB?

[Hessner]

Hi,

havent seen the actual "raw" SQL query, but I expect a prober select with join and where in the right places.

As I would do it by hand.

I expect there are an easy way to "dump" the SQL query, but haven't looked for it - yet.

[Thomas]

Hello Bo  & Sathish,

you can see the SQL excecuted when turning the logging facilities on; this can be done from the OpenAccess menu->Configuration->Backend Configuration Settings.

As for your other question:

Currently, the LINQ projection is not pushed to the server. That means, the 'default fetch group' is loaded as if it had been requested by an OQL query 'select * from UserRoleExtent ....'. Later, the LINQ execution is accessing the properties it needs and projects them into a new, non-persistent type instance. That gives also a hint how to avoid loading to many fields: using the DefaultFetchGroupAttribute to set off the loading of fields which are not necessary in this circumstance.

All the best,
Thomas