Note: the query optimizer considers using a functional index when the index expression is used in a relational expression or as an argument to one of the operator class functions.
注意:当索引表达式被用于关系表达式,或作为某个操作符类函数的参数时,查询优化器将考虑使用函数索引。
Update 14 USES the relational column value "CID" in the transform expression to produce a new element "customerid" as the first element under the root element "customerinfo."
更新14在转换表达式中使用关系列“CID”生成新元素“customerid”并让它成为根元素“customerinfo”下的第一个元素。
To do this, an XPath expression is used to identify the portion of the XML data, normally a specific XML text node, that returns each relational data value.
为此,需使用一个XPath表达式来识别由XML数据组成的部分,通常为一个特定的XML文本节点,它会返回所有关系数据值。
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