Column <tablename>_id referenced in foreign key not found - postgresql

Question

I'm going through 7 Databases in 7 Weeks.
In PostgreSQL, I created a venues table that has a SERIAL venue_id column.
output of \d venues
Table "public.venues"
Column | Type | Modifiers
----------------+------------------------+-----------------------------------------------------------
venue_id | integer | not null default nextval('venues_venue_id_seq'::regclass)
name | character varying(255) |
street_address | text |
type | character(7) | default 'public'::bpchar
postal_code | character varying(9) |
country_code | character(2) |
Indexes:
"venues_pkey" PRIMARY KEY, btree (venue_id)
Check constraints:
"venues_type_check" CHECK (type = ANY (ARRAY['public'::bpchar, 'private'::bpchar]))
Foreign-key constraints:
"venues_country_code_fkey" FOREIGN KEY (country_code, postal_code) REFERENCES cities(country_code, postal_code) MATCH FULL
The next step is to create an event table that references venue_id with a foreign key.
I'm trying this:
CREATE TABLE events (
event_id SERIAL PRIMARY KEY,
title text,
starts timestamp,
ends timestamp,
FOREIGN KEY (venue_id) REFERENCES venues (venue_id));
And I get this error:
ERROR: column "venue_id" referenced in forgein key not found
What's wrong?

Answer 1

you need to initialize the foreign key column too. see here http://www.postgresql.org/docs/current/static/ddl-constraints.html#DDL-CONSTRAINTS-FK
source & credit from #mu is too short

Answer 2

I'm going through the second edition of this book, so things might have changed slightly.
To create the table, you explicitly have to declare the venues_id as a column in your table, just like the rest of your columns:
CREATE TABLE events (
event_id SERIAL PRIMARY KEY,
title text,
starts timestamp,
ends timestamp,
venue_id integer, -- this is the line you're missing!
FOREIGN KEY (venue_id)
REFERENCES venues (venue_id) MATCH FULL
);
Once you have executed that, the table is created:
7dbs=# \dt
List of relations
Schema | Name | Type | Owner
--------+-----------+-------+----------
public | cities | table | postgres
public | countries | table | postgres
public | events | table | postgres
public | venues | table | postgres