SELECT isbn, title, price, price * 0.06 AS sales_tax FROM Book WHERE price > 100.00 ORDER BY title; Queries can be nested so that the results of one query can be used in another query via a relational operator or aggregation function.
SELECT isbn, title, price, price * 0.06 AS sales_tax FROM Book WHERE price > 100.00 ORDER BY title; 查询可以嵌套，以便一个查询的结果可以通过关系运算符或聚合函数在另一个查询中使用。