Fix to #23779 - TryRewriteEntityEquality and NotEqual comparison of CompositePrimaryKey

[maumar]

When comparing composite key entities we were comparing the constituent keys and combining them with AndAlso. For not equal comparison we were still comparing the keys using !=, but we didn't flip the combining operator to OrElse.

Fixes #23779

[dmitry-lipetsk]

Could you look to this code also?

efcore/src/EFCore.Relational/Query/RelationalSqlTranslatingExpressionVisitor.cs

Lines 1345 to 1357 in 81aaca8

	result = Visit(
	primaryKeyProperties1.Select(
	p =>
	{
	var comparison = Expression.Call(
	_objectEqualsMethodInfo,
	Expression.Convert(CreatePropertyAccessExpression(nonNullEntityReference, p), typeof(object)),
	Expression.Convert(Expression.Constant(null, p.ClrType.MakeNullable()), typeof(object)));
	return nodeType == ExpressionType.Equal
	? (Expression)comparison
	: Expression.Not(comparison);
	}).Aggregate((l, r) => nodeType == ExpressionType.Equal ? Expression.OrElse(l, r) : Expression.AndAlso(l, r)));

It is very strange, that Equal case uses OrElse operator and NotEqual case uses AndAlso.

---

If this is rule for comparison with NULL (entity equal to NULL, when any part contains NULL), then this code is ok...

[maumar]

@dmitry-lipetsk wrt null comparison, this is correct. We consider null key when any of the parts has null value