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Re: [Gnumed-devel] need SQL help
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From: |
Karsten Hilbert |
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Subject: |
Re: [Gnumed-devel] need SQL help |
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Date: |
Sat, 3 May 2003 01:05:57 +0200 |
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User-agent: |
Mutt/1.3.22.1i |
> I think what you need is an outer join (which ensures each
> row in the table is mentioned at least once:
> select a.substance, cn.value from allergy a left outer join clin_narrative
> cn on (a.id_comment = cn.id);
> cn.value will be NULL is a value is not found.
Looks about right. I'll wander off learning more about joins.
Karsten
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