Re: Get the max(value1, value2, value3) from a table

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От Erik Jones
Тема Re: Get the max(value1, value2, value3) from a table
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Msg-id 53C367DF-24B3-425C-9EE7-BBA7336D3A89@myemma.com
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Ответ на Re: Get the max(value1, value2, value3) from a table  ("Scott Marlowe" <scott.marlowe@gmail.com>)
Список pgsql-sql
On Jan 7, 2008, at 4:43 PM, Scott Marlowe wrote:

> On Jan 7, 2008 4:38 PM, Josh Williams <joshwilliams@ij.net> wrote:
>> On Mon, 2008-01-07 at 17:03 -0500, Emi Lu wrote:
>>> select ?max?(col1, col2, col3) as result;
>>> will return
>>>
>>> result
>>> -------
>>> 5
>>> 8
>>> 12
>>>
>>> (3 rows)
>>
>> 8.1 (I believe?) introduced GREATEST(), which does precisely what
>> you're
>> looking for.
>
> How would greatest give him three rows like that?  Maybe I'm
> misunderstanding what the OP was asking for...

His test data was:

col1  col2  col3
----------------------
1          5   2
8          1   3
12        1  1

So, SELECT test(col1, col2, col3);

returning

test
-----
5
8
12

Is giving the max of the three columns for each row.
Erik Jones

DBA | Emma®
erik@myemma.com
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