Re: My honours project - databases using dynamically attached entity-properties

From: Gregory Stark <stark(at)enterprisedb(dot)com>
To: <mark(at)mark(dot)mielke(dot)cc>
Cc: "David Fetter" <david(at)fetter(dot)org>, "Edward Stanley" <Edward(dot)Stanley(at)mcs(dot)vuw(dot)ac(dot)nz>, "Richard Huxton" <dev(at)archonet(dot)com>, "Sean Utt" <sean(at)strateja(dot)com>, "Andrew Hammond" <andrew(dot)george(dot)hammond(at)gmail(dot)com>, <josh(at)agliodbs(dot)com>, <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: My honours project - databases using dynamically attached entity-properties
Date: 2007-03-14 15:48:31
Message-ID: 873b47n7w0.fsf@stark.xeocode.com
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<mark(at)mark(dot)mielke(dot)cc> writes:

> On Wed, Mar 14, 2007 at 03:25:48PM +0000, Gregory Stark wrote:
>> <mark(at)mark(dot)mielke(dot)cc> writes:
>> > On Wed, Mar 14, 2007 at 02:28:03PM +0000, Gregory Stark wrote:
>> >> "David Fetter" <david(at)fetter(dot)org> writes:
>> >> > CREATE TABLE symptom (
>> >> > symptom_id SERIAL PRIMARY KEY, /* See above. */
>> >> > ...
>> >> > );
>> >> > CREATE TABLE patient_presents_with (
>> >> > patient_id INTEGER NOT NULL REFERENCES patient(patient_id),
>> >> > symptom_id INTEGER NOT NULL REFERENCES symptom(symptom_id),
>> >> > UNIQUE(patient_id, symptom_id)
>> >> > );
>> >> I'm just glad I don't have your doctor. I hope mine doesn't think
>> >> symptoms are all boolean values.
>> > Where is the boolean above? It is M:N, with each having whatever data
>> > is required.
>> No, the above schema can only show whether a patient has or doesn't have a
>> symptom. There is nowhere to store *where* the pain, inflammation, swelling,
>> aneurism, etc is, or how severe it is, or when it occurred, etc.
>
> What do you think the '...' is in the symptom table? :-)

Ah, I did in fact miss that. So then this is just a standard EA schema. I
thought you were on the other side of the debate?

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com

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