Re: O'Reilly interview with Date
From: Paul <paul_at_test.com>
Date: Fri, 12 Aug 2005 10:58:53 +0100
Message-ID: <42fc72dd$0$17484$ed2e19e4_at_ptn-nntp-reader04.plus.net>
>
> Foreign keys are distiguished by suffix and prefix, in the example above on
> of them has the suffix "_TO", so when I specify a query I specify that
> suffix and now it can identify the fk definition and from there the
> columns.
Date: Fri, 12 Aug 2005 10:58:53 +0100
Message-ID: <42fc72dd$0$17484$ed2e19e4_at_ptn-nntp-reader04.plus.net>
>>OK maybe I'm being dense here, but when you now specify your two tables, >>"examples" and "examples_xref", how does the system know which of the >>foreign key constraints to use to generate the join?
>
> Foreign keys are distiguished by suffix and prefix, in the example above on
> of them has the suffix "_TO", so when I specify a query I specify that
> suffix and now it can identify the fk definition and from there the
> columns.
OK but if you have to specify the foreign key, why not just specify the columns in the firstplace?
What if you have a non-standard join? For example start_date and end_date columns and you want to join where some date is between these two?
Paul. Received on Fri Aug 12 2005 - 11:58:53 CEST