Question

I have a web application using EF4. I am somewhat new to EF and now trying to implement change Audit.I tried to do this by trapping the SavingChanges event of the Context Class as below

partial void OnContextCreated()
        {
            this.SavingChanges += new EventHandler(TicketContainer_SavingChanges);

        }

So the event handler accesses the changed records by the following

this.ObjectStateManager.GetObjectStateEntries(
             EntityState.Added | EntityState.Modified);

This works fine and I am creating column level audit for selected tables. Every table/entity has an ID field which is an identifier with columnName=”ID”. So in my audit routine I simply accesses data from column with name “Id” to get the ID of audited record.

The problem I face is during insert . The new record has no ID yet as it is an identity column in the database and is always 0.

One solution I can think of is using GUID for all Ids.But is there a way to implement this using standard int32 Identity Ids?

thanks

Answer 1

When we insert data through EF the identity column is not generted while insertion. To get the Id of Identity columns we have to insert the data first then only we can get the Id of coulmn.

please go through the below which might be helpful to you.
http://www.codeproject.com/KB/database/ImplAudingTrailUsingEFP1.aspx