清单6创建一个标量函数，它从输入文档中提取出一个特定的xml元素。然后，在一个简单的SQL查询中调用此函数，从而返回给定的客户的姓名。
Listing 6 creates a scalar function that extracts a given XML element from an input document and shows how this function can be invoked in a simple SQL query to return the name of a given customer.
SHIP3操作符包含一个语句，该语句表明标量子查询的结果放在一个主机变量中。
The SHIP3 operator contains the statement that shows the result of the scalar subquery being bound in as a host variable.
标量子查询是一种嵌入式查询，返回包含单个列的单个行，本质上就是单个值，该值称为标量。
A scalar subquery is an embedded query that returns a single row that contains a single column — essentially, a single value, which is known as a scalar.
应用推荐