<[EMAIL PROTECTED]> writes: > On Wed, Mar 14, 2007 at 03:25:48PM +0000, Gregory Stark wrote: >> <[EMAIL PROTECTED]> writes: >> > On Wed, Mar 14, 2007 at 02:28:03PM +0000, 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. >> > 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 ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
