On Wed, Jan 6, 2010 at 8:51 PM, Yan Cheng Cheok <yccheok@xxxxxxxxx> wrote: > I came across a lot of similar example for foreign key > > CREATE TABLE orderinfo > ( > orderinfo_id serial , > customer_id integer NOT NULL, > date_placed date NOT NULL, > date_shipped date , > shipping numeric(7,2) , > CONSTRAINT orderinfo_pk PRIMARY KEY(orderinfo_id), > CONSTRAINT orderinfo_customer_id_fk FOREIGN KEY(customer_id) REFERENCES > customer(customer_id) > ); > > instead of let customer_id being type as integer, can i let it be serial? is there any difference? > > if the table referenced by customer_id is having primary key typed big serial, customer_id shall be declared as bigint ? serial and big serial are basically syntactic sugar for creating the table with an int / bigint, create a sequence, create a default for the bigint field, and setting a dependency in the system catalogs for the sequence to the table. So, yep, a serial / bigserial is equivalent to int / bigint from an FK point of view. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
