PostgreSQL Autoincrement
Yes, SERIAL is the equivalent function.
CREATE TABLE foo (
id SERIAL,
bar varchar
);
INSERT INTO foo (bar) VALUES ('blah');
INSERT INTO foo (bar) VALUES ('blah');
SELECT * FROM foo;
+----------+
| 1 | blah |
+----------+
| 2 | blah |
+----------+
SERIAL is just a create table time macro around sequences. You can not alter SERIAL onto an existing column.
You can use any other integer data type, such as smallint
.
Example :
CREATE SEQUENCE user_id_seq;
CREATE TABLE user (
user_id smallint NOT NULL DEFAULT nextval('user_id_seq')
);
ALTER SEQUENCE user_id_seq OWNED BY user.user_id;
Better to use your own data type, rather than user serial data type.
If you want to add sequence to id in the table which already exist you can use:
CREATE SEQUENCE user_id_seq;
ALTER TABLE user ALTER user_id SET DEFAULT NEXTVAL('user_id_seq');