I'm using Entity Framework 4.0. Now I need to restrict access to a table while I'm reading from it or writing to it. Probably that's about transaction isolation level.
How do I do that?
Update
here is what I have
using (var db = new MyDb())
{
using (TransactionScope scope = new TransactionScope())
{
var item = db.MyItems.Single(x => x.Id == 5);
item.Price = 12;
db.SaveChanges();
scope.Complete();
}
}
However, when I put a breakpoint at any line inside using (TransactionScope scope
and when I'm stopping there and then I go to Sql Server Management Studio and doing a select query (or even update!) from a table that is using inside a transaction, I'm not getting an error for some reason. But why? It must not allow me to read a data while a transaction is executing.
Best Answer
By default, a Transaction has an IsolationLevel of Serializable. Serializable is the highest level. It requires that the transaction completes before any other transaction is allowed to operate on the data.
It has the following restrictions:
This is a great blog post that explains how to use Transactions with the Entity Framework: Entity Framework transaction scope examples
UPDATE
In Entity Framework 6 the default IsolationLevel is changed to READ_COMMITTED_SNAPSHOT for databases created using Code First, potentially allowing for more scalability and fewer deadlocks. See the future spec of EF 6