composite foreign key one field constant?

Basically, I want to create a foreign key to a table that has a composite primary key of two fields, but in my table, i'm only storing one of the values, because the other one is always constant.

First table: contain data that ends up in my GUI pulldowns for various data items. Each type has allowable values.

CREATE TABLE CONTROLLED_VOCABULARY (

      TYPE            VARCHAR2(64) NOT NULL,
      VALUE           VARCHAR2(64) NOT NULL,
      DESCRIPTION     VARCHAR2(256)
      constraint CV_PK PRIMARY KEY (MIMETYPE, VALUE)

INSERT INTO CONTROLLED_VOCABULARY VALUES
( 'template-type', 'templateOne', 'some desc');
INSERT INTO CONTROLLED_VOCABULARY VALUES
( 'template-type', 'templateTwo', 'some desc');

Other table (WORKDETAILS) I have a
column TEMPLATETYPE that I want to reference the value of the first table where the TYPE='template-type'

alter table WORKDETAILS add
  constraint WORKDETAILS_TEMPLATE_FK
  foreign key ('template-type', TEMPLATETYPE)   references CONTROLLED_VOCABULARY (type, value) ;

This was not allowed... i also tried using a check to do a select from controlled_vocabulary where type='...' but that didn't work either...

Is this possible.. syntax? do i have to use a trigger/proc? i don't want to have to store 'template-type' in one of my fields because it's always the same value.

Cheers,
-Don Received on Tue Nov 19 2002 - 10:52:01 CST