Entity Framework with NOLOCK

Question

How can I use the NOLOCK function on Entity Framework? Is XML the only way to do this?

Answer 1

No, not really - Entity Framework is basically a fairly strict layer above your actual database. Your queries are formulated in ESQL - Entity SQL - which is first of all targeted towards your entity model, and since EF supports multiple database backends, you can't really send "native" SQL directly to your backend.

The NOLOCK query hint is a SQL Server specific thing and won't work on any of the other supported databases (unless they've also implemented the same hint - which I strongly doubt).

Marc

Answer 2

No, but you can start a transaction and set the isolation level to read uncommited. This essentially does the same as NOLOCK, but instead of doing it on a per table basis, it will do it for everything within the scope of the transaction.

If that sounds like what you want, here's how you could go about doing it...

//declare the transaction options
var transactionOptions = new System.Transactions.TransactionOptions();
//set it to read uncommited
transactionOptions.IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted;
//create the transaction scope, passing our options in
using (var transactionScope = new System.Transactions.TransactionScope(System.Transactions.TransactionScopeOption.Required, transactionOptions))
{
    //declare our context
    using (var context = new MyEntityConnection())
    {
        //any reads we do here will also read uncomitted data
        //...
        //...
    }
    //don't forget to complete the transaction scope
    transactionScope.Complete();
}