Gregory Stark wrote:
> "David Fetter" <[EMAIL PROTECTED]> 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.
With a unique across (patient_id,symptom_id) you could have a single
patient with as many unique symptoms as could be listed.
Joshua D. Drake
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