I've been playing around with Blinq today and everything was working fine until I decided to add a few more relationships in my database and then rerun blinq. Now when ever I try to update a record in any of the tables I get the ROW NOT FOUND OR CHANGED error. I realize there is a way to turn off the optimistic concurrency check, but I'm just wondering why it's necessary and why it suddenly occured after adding some simple relationships.

Just trying to understand the process a little better. Thanks.

My stack trace is below:

OptimisticConcurrencyException: Row not found or changed.]
   System.Data.DLinq.ChangeProcessor.ThrowOptimisticConcurrencyException(List`1 failedUpdates, Int32 totalUpdatesAttempted) +171
   System.Data.DLinq.ChangeProcessor.SubmitChanges(ConflictMode failureMode) +522
   System.Data.DLinq.DataContext.SubmitChanges(ConflictMode failureMode) +229
   System.Data.DLinq.DataContext.SubmitChanges() +6
   TblOffice.Update(TblOffice original_x, TblOffice x) in c:\inetpub\wwwroot\TL\App_Code\StaticMethods.vb:462

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +0
   System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +72
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +358
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +29
   System.Web.UI.WebControls.ObjectDataSourceView.InvokeMethod(ObjectDataSourceMethod method, Boolean disposeInstance, Object& instance) +482
   System.Web.UI.WebControls.ObjectDataSourceView.InvokeMethod(ObjectDataSourceMethod method) +38
   System.Web.UI.WebControls.ObjectDataSourceView.ExecuteUpdate(IDictionary keys, IDictionary values, IDictionary oldValues) +2573
   System.Web.UI.DataSourceView.Update(IDictionary keys, IDictionary values, IDictionary oldValues, DataSourceViewOperationCallback callback) +78
   System.Web.UI.WebControls.GridView.HandleUpdate(GridViewRow row, Int32 rowIndex, Boolean causesValidation) +1215
   System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +858
   System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) +95
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +35
   System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) +117
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +35
   System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +115
   System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +163
   System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +174
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102

Do you have a column of type DateTime with high precision?  From the readme:

·         Tables with columns of type DateTime with higher precision than seconds do not update correctly. Blinq creates BoundField objects for DateTime fields that do not contain precision beyond seconds, so updates with DateTime fields with high precision that participate in optimistic concurrency fail. To fix this, do one of the following:

o        Change the precision displayed by the BoundField object by setting DataFormatString="{0:o}", HtmlEncode=false, and ApplyFormatInEditMode=true.

o        Designate the DateTime field as never participating in optimistic concurrency. See "Changing a Field’s Update Mode" earlier in this document to change the update mode for this column. Use this option carefully—removing this column from participating in optimistic concurrency will allow overwrites of the value to succeed even if the database’s value has been changed.

Hi,

I don't know if you can help me to solve my problem. I am just writting to you because you had the same problem and also there was a solution from Polita to solve your problem. I am not sure if the reply from Polita was helpful to y

Hi,

I don't know if you can help me to solve my problem. I am just writting to you because you had the same problem of not be able to update existing rpws and as well as there was a solution from Polita to solve your problem. I am not sure if the reply from Polita was helpful to you. I have tried the same solution to solve my problem but it did not help me.

The second solution (Reply from Polita to solve your problem) was:

Designate the DateTime field as never participating in optimistic concurrency. See "Changing a Field’s Update Mode" earlier in this document to change the update mode for this column. Use this option carefully—removing this column from participating in optimistic concurrency will allow overwrites of the value to succeed even if the database’s value has been changed.

The above paragraph asking me to see "Changing a Field’s Update Mode" to set the DateTime field as never participating in optimistic concurrency. But I don't know exactly where in my application I can get this optimistic concurrency property. so that I can change it. If you have any idea, please let me know.

 Also for your reference here is my error trace:

Actually Polita's answer was very helpful. The document that she points you to has all the answers, but basically, in you App_code folder you'll have a .vb or .cs file named after your database. In there is a long list of database properties, associates and such. You need to find any potential problem columns (dates in my case) and change (or add) the updatecheck field to the top of the property.

In the file look for something like this

Thanks very much for your quick reply. That was really helpful. Though your code help me to sort out the problem partially, I have figure a BUG in the BLINQ.

 Blinq does not work with timestamp in the database. So, I had to remove "IsVersion=true" from the code. Finally it works for me.

The code before:

[Column(Storage="_SSWTimestamp", DBType="rowversion NOT NULL", IsVersion=true]

After:

Hello,

I have found another instance where this problem occurs (on any type of column).  In the ObjectDataSource, when a column's Visible property is set to false, the value it gets when the BO is created seems to be default(Type).  Just to see if that was the problem, I set the column's value in the Updating event.  The problem was still there.  For the update to work, I either have to set the column visible or set the UpdateCheck's column attribute to Never.  I chose the latter in my case.

Why does a column get a value of default(Type) when it is not visible in the GridView (when the BO is created)?  It should be set to the original record's field value.

BTW, I really like Blinq, thanks !!

Polita,

What Marc has found with updating (and I know about the fix there) I found the same with deleting, making columns invisible (and only some at that) break the delete as I assume its expecting all the values back to check before deleting. How do I get around this ?

Thanks

Zeid

BTW Thanks for Blinq....

Polita,

Thanks, but its not that - best way to explain is with a blinq website pointing at the northwind database.

If you go to the orderdetails page. Working with Quantity, Discount or Unit Price,  try to delete one column at a time, you will find the the delete operation stops working with the "You have specified that your delete method compares all values on ObjectDataSource 'OrderDetailsDataSource', but the dictionary passed in for oldValues is empty.  Pass in a valid dictionary for delete or change your mode to OverwriteChanges", once these three have all been set to "visible=false" within the grid control.

I have done this in any order and still the same result.

Adding UpdateCheck=System.Data.DLinq.UpdateCheck.Never has no discernable affect. If say any one or two of the three colums are visible the delete operation works.

Going to the ObectDataSource and setting it to OverwriteChanges makes it start working - however is this the only way to make delete operations work when you want to make certain fields invisible on the grid?.

The question I have I guess is why is it working in this way.... 

Thanks

Zeid

Hi there,

I don't know if you can help me with this one. Like update now I am having problem with inserting new rows into the database. It throws me the below error.

I am using timestamp in my database.  

It would be a great pleasure if any help. thanks 

memam 

ERROR msg:

Cannot insert an explicit value into a timestamp column. Use INSERT with a column list to exclude the timestamp column, or insert a DEFAULT into the timestamp column.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Cannot insert an explicit value into a timestamp column. Use INSERT with a column list to exclude the timestamp column, or insert a DEFAULT into the timestamp column.

Source Error:

Line 16:       Dim db = CreateDataContext()
Line 17:       db.AffiliateBooks.Add(x)
Line 18:       db.SubmitChanges()
Line 19:       Return 1
Line 20:     End Function

[SqlException (0x80131904): Cannot insert an explicit value into a timestamp column. Use INSERT with a column list to exclude the timestamp column, or insert a DEFAULT into the timestamp column.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +95
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +82
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +346
   System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +3244
   System.Data.SqlClient.SqlDataReader.ConsumeMetaData() +52
   System.Data.SqlClient.SqlDataReader.get_MetaData() +130
   System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +371
   System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +1121
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +334
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +45
   System.Data.SqlClient.SqlCommand.ExecuteReader(Comm