I'm seeing an odd issue when using a TransactionScope, in which the first CRUD operation performed never seems to use the scope's isolation level.
For example, assume code like this (for the record, I am well aware that the TransactionScope is not needed here, I am trying to illustrate what I think is a bug):
A SQL Profiler trace of the above seems to show that the requested isolation level - serializable - is not used with the first save.
An error is not thrown, but based on the trace it does seem that the isolation level is initially ignored.
We see this behavior in EF 5, and in EF 6 RC1.
For example, assume code like this (for the record, I am well aware that the TransactionScope is not needed here, I am trying to illustrate what I think is a bug):
[TestMethod] publicvoid TestTransactionIsolation() { var options = new TransactionOptions() { IsolationLevel = IsolationLevel.Serializable, Timeout = TimeSpan.FromMinutes(1) }; using (var transaction = new TransactionScope(TransactionScopeOption.Required, options)) { using (var ctx = new NorthwindEntities()) { var cust1 = Customer.CreateCustomer(Guid.NewGuid(), "company a"); ctx.AddToCustomers(cust1); ctx.SaveChanges(); var cust2 = Customer.CreateCustomer(Guid.NewGuid(), "company b"); ctx.AddToCustomers(cust2); ctx.SaveChanges(); } transaction.Complete(); } }
Audit Login set transaction isolation level read committed
RPC:Completed exec sp_executesql N'INSERT [dbo].[Customer] …
Audit Logout
RPC:Completed exec sp_reset_connection
Audit Login set transaction isolation level serializable
RPC:Completed exec sp_executesql N'INSERT [dbo].[Customer]…
Audit Logout
RPC:Completed exec sp_reset_connection
Audit Login set transaction isolation level serializable
Audit Logout An error is not thrown, but based on the trace it does seem that the isolation level is initially ignored.
We see this behavior in EF 5, and in EF 6 RC1.