protected Expression VisitIn(InExpression inExpression) { var canOptimize = _canOptimize; _canOptimize = false; _isNullable = false; var item = (SqlExpression)Visit(inExpression.Item); var isNullable = _isNullable; _isNullable = false; var subquery = (SelectExpression)Visit(inExpression.Subquery); isNullable |= _isNullable; _isNullable = false; var values = (SqlExpression)Visit(inExpression.Values); _isNullable |= isNullable; _canOptimize = canOptimize; return(inExpression.Update(item, values, subquery)); }