foreign key constraint to multiple tables - Mailing list pgsql-novice

From Kevin McCarthy
Subject foreign key constraint to multiple tables
Date
Msg-id 4178da10708130914x1f5b0304p21f4ed63f08c7fb5@mail.gmail.com
Whole thread Raw
Responses Re: foreign key constraint to multiple tables
List pgsql-novice
I have a table with a column that will join with one of several tables based on the value of another column. I'm not sure if this column can be set as a foreign key to any of these tables, may be simply bad design on my part. The item_type_id column of a record of 'A' will reference one of the 'type' table records depending upon what the value of the record's item_type column is.

Is there a way to set the item_type_id column in Table A as a foreign key to the other tables depending? Or would there be a better way to design this schema?

TIA

CREATE TABLE ABC(
 id SERIAL PRIMARY KEY,
 item_type character varying(10) NOT NULL,
 item_type_id INTEGER
);

CREATE TABLE typeA(
  typeA_id SERIAL PRIMARY KEY
);

CREATE TABLE typeB(
  typeB_id SERIAL PRIMARY KEY
);

CREATE TABLE typeC(
  typeC_id SERIAL PRIMARY KEY
);


--
Kevin McCarthy
kemccarthy1@gmail.com

pgsql-novice by date:

Previous
From: Tom Lane
Date:
Subject: Re: Install two different versions of postgres which should run in parallel
Next
From: "Jasbinder Singh Bali"
Date:
Subject: Postmaster start up problems (can't create lock file )