Re: unique across two tables - Mailing list pgsql-general

From David Johnston
Subject Re: unique across two tables
Date
Msg-id 021801cc30e1$2e8ed830$8bac8890$@yahoo.com
Whole thread Raw
In response to Re: unique across two tables  (Misa Simic <misa.simic@gmail.com>)
Responses Re: unique across two tables  (Misa Simic <misa.simic@gmail.com>)
Re: unique across two tables  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-general

Misa,

 

Your statement is utterly false simply by virtue of the documentation.

 

Inserts never propagate to other tables in a hierarchy

Indexes/Constraints only apply to individual tables

 

Since inserts do not propagate the base table never sees the records and thus the index on the base table cannot enforce uniqueness.

 

Other caveats and restrictions to the current inheritance implementation can be found in section 5.8 (Inheritance) of the documentation.  It is in the “Data Definition” chapter.

 

David J.

 

 

From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Misa Simic
Sent: Wednesday, June 22, 2011 8:49 AM
To: Tarlika Elisabeth Schmitz
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] unique across two tables

 

Hi Tarlika,

 

I think easy solution could be:

 

create baseTable with just one column as PK

 

TableA inhertis baseTable, it will have inherited Column + additianl tables for TableA

TableB inherits baseTable, it will aslo have inherited Column + additianl tables for TableB

 

Insert in any table TableA or TableB will automatically insert row in baseTable what will fail if value already exist...

 

 

 

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