Inherited Table

Started by Peter Harveyover 24 years ago4 messageshackers
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#1Peter Harvey
pharvey@codebydesign.com

Anyone know how inherited tables are shown on an ERD... both the table
and the connector (if any)?

What I am looking for is how to draw this in the diagram.

Peter

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#2Hannu Krosing
hannu@tm.ee
In reply to: Peter Harvey (#1)
Re: Inherited Table

Peter Harvey wrote:

Anyone know how inherited tables are shown on an ERD... both the table
and the connector (if any)?

What I am looking for is how to draw this in the diagram.

An old S-Designor does it so:

Attachments:

inherit.gifimage/gif; name=inherit.gifDownload
#3Peter Harvey
pharvey@codebydesign.com
In reply to: Peter Harvey (#1)
Re: Inherited Table

Hannu Krosing wrote:

Peter Harvey wrote:

Anyone know how inherited tables are shown on an ERD... both the table
and the connector (if any)?

What I am looking for is how to draw this in the diagram.

An old S-Designor does it so:

Yes. But pgsql does not support multiple inheritance (from what I can
tell) so the extra symbol along the ref line ("can be"/"must be") seems
silly. I am thinking that I should draw the new table slightly diff in
some way just as is done with Views. However; some purests would freak.
<Hmmm>

Thanks

Peter

#4Oliver Elphick
olly@lfix.co.uk
In reply to: Peter Harvey (#3)
Re: Inherited Table

Peter Harvey wrote:

Yes. But pgsql does not support multiple inheritance (from what I can
tell)...

In fact it does:

create table child (col1 text) inherits (parent1, parent2);

Identically named and typed columns in the parents are merged.

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Oliver Elphick Oliver.Elphick@lfix.co.uk
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