Re: syntax of joins
| От | Pavel Stehule |
|---|---|
| Тема | Re: syntax of joins |
| Дата | |
| Msg-id | CAFj8pRAeQO6cJRTWQdp+LsTS8aK+LpQwRLP1cv5PPc=Fsh+VSw@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: syntax of joins (Rob Sargent <robjsargent@gmail.com>) |
| Ответы |
Re: syntax of joins
|
| Список | pgsql-sql |
2012/4/6 Rob Sargent <robjsargent@gmail.com>: > On 04/06/2012 01:23 PM, Pavel Stehule wrote: >> >> Hello >> >> 2012/4/6 Andreas<maps.on@gmx.net>: >>> >>> hi, >>> >>> is there a disadvantage to write a join as >>> >>> select * >>> from a, b >>> where a.id = b.a_id; >>> >> >>> over >>> >>> select * >>> from a join b on a.id = b.a_id; >>> >> >> yes - newer notation has some advantages >> >> * clean specification join predicate and filter predicate >> * simple adaptability to outer join >> * increased protection against copy/paste bug that introduce Cartesian >> product >> >> Regards >> >> Pavel Stehule >> >>> -- >>> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) >>> To make changes to your subscription: >>> http://www.postgresql.org/mailpref/pgsql-sql >> >> > In other words, no disadvantage :) > Hard to say - for man who fixed critical cartesian products :) in queries Pavel > -some cranky old guy who still misses "retrieve" > > > -- > Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-sql
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