Re: simple (?) join

On Sat, 26 Sep 2009 14:54:24 -0400, justin wrote about Re: [SQL] simple
(?) join:

[snip]
>Quoting Gary
>"How can I select all from orders and the last (latest) entry from the
>orders_log?"

In that case, a simple Cartesian product will do:

SELECT o.*, maxi.ts
FROM orders AS o,
(SELECT MAX(ol_timestamp) AS ts FROM orders_log) AS maxi;

Since the cardinality of the subquery "maxi" is 1, it will give a result
set with cardinality of the complete orders table.

I don't understand why anybody would want to do that. [De gustibus ... ]
--
Regards,

Dave [RLU #314465]
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david(dot)w(dot)noon(at)ntlworld(dot)com (David W Noon)
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