Re: Extracting unique data from tables/views question

Can you show me what this query outputs, please?

SELECT fk_patient,MAX(observation_date) as observation_date
FROM documents.vwobservations
WHERE loinc = '4548-4'
GROUP BY fk_patient

Best,
Oliver

----- Original Message -----
From: "richard terry" <rterry(at)pacific(dot)net(dot)au>
To: "Oliveiros d'Azevedo Cristina" <oliveiros(dot)cristina(at)marktest(dot)pt>;
"PostgreSQL - newbie" <pgsql-novice(at)postgresql(dot)org>
Sent: Wednesday, December 29, 2010 1:37 PM
Subject: Re: [NOVICE] Extracting unique data from tables/views question

> On Thursday 30 December 2010 00:27:47 you wrote:
>> SELECT DISTINCT fk_patient, observation_date, value_numeric
>> FROM documents.vwobservations a
>> NATURAL JOIN
>> (SELECT fk_patient,MAX(observation_date) as observation_date
>> FROM documents.vwobservations
>> WHERE loinc = '4548-4'
>> GROUP BY fk_patient) b
>> ORDER BY fk_patient
>>
>
> Runs ok, but gives weird results all the same patient key, and not sure
> which
> ones are hba1c.
>
> ??
>
> Regards
>
> richard
>
> 52;"2010-07-02";0.01
> 52;"2010-07-02";0.08
> 52;"2010-07-02";0.43
> 52;"2010-07-02";0.49
> 52;"2010-07-02";1
> 52;"2010-07-02";2.09
> 52;"2010-07-02";2.6
> 52;"2010-07-02";2.8
> 52;"2010-07-02";3.4
> 52;"2010-07-02";3.7
> 52;"2010-07-02";3.89
> 52;"2010-07-02";4.3
> 52;"2010-07-02";4.5
> 52;"2010-07-02";5
> 52;"2010-07-02";6.3
> 52;"2010-07-02";6.6
> 52;"2010-07-02";8
> 52;"2010-07-02";8.9
> 52;"2010-07-02";13.5
> 52;"2010-07-02";14.2
> 52;"2010-07-02";23
> 52;"2010-07-02";25
> 52;"2010-07-02";30
> 52;"2010-07-02";30.5
> 52;"2010-07-02";34
> 52;"2010-07-02";38.2
> 52;"2010-07-02";45
> 52;"2010-07-02";48
> 52;"2010-07-02";60
> 52;"2010-07-02";68
> 52;"2010-07-02";85
> 52;"2010-07-02";97
> 52;"2010-07-02";100
> 52;"2010-07-02";104
> 52;"2010-07-02";136
> 52;"2010-07-02";138
> 52;"2010-07-02";200
> 52;"2010-07-02";202
> 52;"2010-07-02";212
> 52;"2010-07-02";316
> 52;"2010-07-02";
> 53;"2010-07-13";2.2
> 53;"2010-07-13";6.6
> 53;"2010-07-13";26
>
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