I have table containing different types of documents (type A, B and C).
Each document type must have separate sequential ID starting at 1
ID of first inserted record of type A must be set to 1
ID of first inserted record of type B must be also set to 1
ID of second record of type A must be set to 2
etc.
I tried to implement this as
CREATE SEQUENCE a_id_seq;
CREATE SEQUENCE b_id_seq;
CREATE SEQUENCE c_id_seq;
CREATE TABLE documents (
doctype CHAR(1),
id NUMERIC DEFAULT nextval(doctype ||'_dokumnr_seq'),
documentcontents TEXT );
but got an error
ERROR: cannot use column references in default expression
Any idea how to implement this ?
Andrus.