From: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
---|---|
To: | Rob Sargent <robjsargent(at)gmail(dot)com> |
Cc: | pgsql-sql(at)postgresql(dot)org |
Subject: | Re: syntax of joins |
Date: | 2012-04-06 19:46:40 |
Message-ID: | CAFj8pRAeQO6cJRTWQdp+LsTS8aK+LpQwRLP1cv5PPc=Fsh+VSw@mail.gmail.com |
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Thread: | |
Lists: | pgsql-sql |
2012/4/6 Rob Sargent <robjsargent(at)gmail(dot)com>:
> On 04/06/2012 01:23 PM, Pavel Stehule wrote:
>>
>> Hello
>>
>> 2012/4/6 Andreas<maps(dot)on(at)gmx(dot)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
>>
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>>
>>
> 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"
>
>
> --
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