Thread: Inherited Table

Inherited Table

From
Peter Harvey
Date:
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

-- 
+---------------------------
| Data Architect
| your data; how you want it
| http://www.codebydesign.com
+---------------------------


Re: Inherited Table

From
Hannu Krosing
Date:
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:
Attachment

Re: Inherited Table

From
Peter Harvey
Date:
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


Re: Inherited Table

From
"Oliver Elphick"
Date:
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.

-- 
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight                              http://www.lfix.co.uk/oliver
PGP: 1024R/32B8FAA1: 97 EA 1D 47 72 3F 28 47  6B 7E 39 CC 56 E4 C1 47
GPG: 1024D/3E1D0C1C: CA12 09E0 E8D5 8870 5839  932A 614D 4C34 3E1D 0C1C
========================================   "Behold, I stand at the door, and knock; if any man      hear my voice, and
openthe door, I will come in to      him, and will sup with him, and he with me."
 Revelation 3:20