NHibernate stateless session – What is the data alias?

table Orders
id | customer_id | quantity
--------- ------------------
1 | 1 | 5
2 | 1 | 20


var orders = statelessSession.Query().ToList();
orders[0].Customer.HasDiscount = true;
Assert.False(orders[0].Customer == orders[1]. Customer);
Assert.False(orders[1].Customer.HasDiscount);

// while

var orders = session.Query( ).ToList();
orders[0].Customer.HasDiscount = true;
Assert.True(orders[1].Customer.HasDiscount);

Suitable for stateless session interface state NHibernate documentation, which includes:

Stateless sessions are vulnerable to data aliasing effects, due to the
lack of a first-level cache.

I can’t find a solution Explanation. What does ‘data alias effect’ mean?

If you can give an example… that’d be great.

Consider the following example

table Orders
id | customer_id | quantity
--------------------- ------
1 | 1 | 5
2 | 1 | 20


var orders = statelessSession.Query().ToList( );
orders[0].Customer.HasDiscount = true;
Assert.False(orders[0].Customer == orders[1].Customer);
Assert.False(orders [1].Customer.HasDiscount);

// while

var orders = session.Query().ToList();
orders[ 0].Customer.HasDiscount = true;
Assert.True(orders[1].Customer.HasDiscount);

Therefore, when using stateless sessions, customers are not the same instance, so they cannot be viewed To update, and ReferenceEquals will return false. You have two aliases for the same customer