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Microsoft SQL Server
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SQL Server 2008
>2) Speaking of ANSI standard, Common Table Expressions "are" part of the ANSI-99 standard. :)
>CTEs are available in Oracle, MySQL, MS SQL (since 2005), and other DBs as well.
Interesting - had not realized the ANSI part and not really thought about it (part being that the largest part of SQL I code still uses vfp getting no further updates)
>They are functionally equivalent of derived table expressions. Some developers love them, some don't. As for readable and maintainable, that's a matter of opinion.
>Unfortunately, many online sites (and maybe even Wikipedia) refer to CTEs as "temporary named result sets". They're not result sets. It is simply a derived table subquery, placed "above" the outer query that refers to it. It's basically syntax sugar - some like it, some find it too heavy/sweet.
>Yes, they are not a replacement for temp tables. If one needs to store a result set and then perform many subsequent operations beyond what a derived table subquery can do, then yes, a temp table will be better.
I you know for sure from top of your head: Is that defined as well or a [commonly used] implementation detail ? Had mentally categorized it thusly, but as above: did not look en detail.
tia
thomas
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