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...
Kind Regards,
Misa
2011/6/20 Tarlika Elisabeth Schmitz
<postgresql4@numerixtechnology.de>I have two tables, town and townalias, the latter containing alternative
town names.
I would like to ensure that a town name is unique per
country-region across the two tables.
Can I do this with a constraint ot do I need to implement the logic via
trigger?
=========
PostgreSQl 8.4
CREATE TABLE town
(
country_fk character varying(3) NOT NULL,
region_fk character varying(3) NOT NULL,
id serial NOT NULL,
"name" character varying(50) NOT NULL
)
CREATE TABLE townalias
(
country_fk character varying(3) NOT NULL,
region_fk character varying(3) NOT NULL,
town_fk integer NOT NULL,
id serial NOT NULL,
"name" character varying(50) NOT NULL,
CONSTRAINT town_townalias_fk FOREIGN KEY (country_fk, region_fk,
town_fk) REFERENCES town (country_fk, region_fk, id)
)
--
Best Regards,
Tarlika Elisabeth Schmitz
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