当我从客户端应用程序调用sql存储过程时，是否可能引发DBCurrencyException？

Question

I've got a task (Im a student). I need to call a DBCurrencyException. Is it possible to raise a DBCurrencyException when Im calling sql stored procedures from my client app that changes database data? is it possible?

Answer 1

I'm not sure about your problem due to you don't provide your code.

but.... I hope this article can help you http://msdn.microsoft.com/en-us/library/ms171936%28v=vs.110%29.aspx

Answer 2

An ADO.Net Dataset uses Optimistic Concurrency by default. If an attempt is made to update a row to the database when the row no longer exists in the database then the result is the error: Concurrency violation: the UpdateCommand affected 0 of the expected 1 records.

Here is the scenario where that error can occur.

// data row has been added 
DataRow dr= null;

dtTab = (DataTable)Session("dtTab");

dr = dtTab.Rows(e.RowIndex);

dr.Delete();

dtTab.AcceptChanges();


// If Acceptchanges() being not called, row status will be 
//detached, that will not be updated to database.

//Without updating database Acceptchanges() called.Row status 
//changed to deleted. If this update to database, 
// it will give concurrency error-   
// because row no longer exist in database. 

The reason for the error became apparent. The records in the row in the table didn't exist in the database. However, the DeleteCommand was trying to remove them from the Database. And when the data adapter class attempts to delete a record and doesn't see any rows being changed, it assumes that a concurrency violation has occured.

Here is the artcile (The Source of above code) regarding the issue. This article describe when the DBConcurrencyException will raised and how to solve the problem. Please go through the artcicle.

Please try the same things with store procedure, may this will help you.