Its technical term is a common table expression ( CTE ). 用技术术语来说,这叫做公共表表达式(TE)(commontableexpression,CTE)。
The hierarchical query clause is not implemented as common table expression, but the clause is specified as part of a sub-select and must be specified after the WHERE, GROUP BY or HAVING clause. 分级查询子句不是作为公共表表达式(TE)来实现的,而是作为子句被指定为子SELECT语句的一部分,并且必须在指定WHERE、GROUPBY或HAVING子句之后指定。
According to the SQL Standard, the method to evaluate hierarchical or bi-directional data is the Recursive Common Table Expression(TE) ( RCTE ). 根据SQL标准,评估分层或双向数据的方法为递归通用表表达式(TE)(RCTE)。
Instead data-change-operations shall be confined to the top level SELECT or the topmost SELECT of a common table expression ( CTE, also known as the " WITH clause "). 相反,数据更改操作应该限制在公共表表达式(TE)(CTE,也叫做“WITH子句”)的顶层SELECT或最上面的SELECT中。
This second select statement is joined with the Common Table Expression(TE) ( CTE ) itself by linking parent to child data. 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(TE)(CTE)联接。