公共表表达式(with子句)允许数据更新操作的高效管道。
Common table expressions (the WITH clause) allow efficient pipelining of data-change-operations.
清单3中的示例显示了使用公共表表达式创建结构化的XML。
The example in Listing 3 shows the creation of structured XML using common table expressions.
注意,已为每个副本组创建了一个公共表表达式(第2、18和38行)。
Notice that for each repetition group a common table expression has been created (lines 2, 18 and 38).
注意,在第45 - 46行中,XML内容来自于最开始的两个公共表表达式。
Notice, in lines 45-46, the XML contents placement from the first two common table expressions.
因此,可能有必要使用公共表表达式重新构造空间查询,以确保只调用一次构造函数。
Therefore, it might be worthwhile to restructure your spatial query to ensure just a single call to the constructor function using common table expressions.
第二个SELECT语句通过将父数据链接至子数据与公共表表达式 (CTE) 联接。
This second select statement is joined with the Common Table Expression (CTE) itself by linking parent to child data.
用技术术语来说,这叫做公共表表达式(common table expression,CTE)。
在本文中,我提供了从oracle型CONNECT BY递归查询语法到DB 2中遵从标准的使用UNION ALL的递归公共表表达式的通用映射。
In this article I provided generic mappings from the Oracle style CONNECT BY recursive query syntax to DB2's standard compliant recursive common table expressions using UNION ALL.
在本文中,我提供了从oracle型CONNECT BY递归查询语法到DB 2中遵从标准的使用UNION ALL的递归公共表表达式的通用映射。
In this article I provided generic mappings from the Oracle style CONNECT BY recursive query syntax to DB2's standard compliant recursive common table expressions using UNION ALL.
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