H2 refuses to create auto_increment for Postgres emulated database - sql

Question

I created an in memory H2 database with JDBC URL
jdbc:h2:~/test;MODE=PostgreSQL;DATABASE_TO_LOWER=TRUE;DEFAULT_NULL_ORDERING=HIGH
The H2 web console refuses to let me do an auto_increment. I've seen serial for Postgres, but that doesn't work either.
At it's simplest, it hates:
create table test(id bigint auto_increment);
Syntax error in SQL statement "create table test(id bigint [*]auto_increment)"; expected "ARRAY, INVISIBLE, VISIBLE, NOT NULL, NULL, AS, DEFAULT, GENERATED, ON UPDATE, NOT NULL, NULL, DEFAULT ON NULL, NULL_TO_DEFAULT, SEQUENCE, SELECTIVITY, COMMENT, CONSTRAINT, COMMENT, PRIMARY KEY, UNIQUE, NOT NULL, NULL, CHECK, REFERENCES, ,, )"; SQL statement:
create table test(id bigint auto_increment) [42001-214] 42001/42001 (Help)
Why do I care:
My code base was failing with NULL not allowed for column "REV". I'm using JPA/Hibernate + Liquibase. In order to try the suggestions at
Hibernate Envers + Liquibase: NULL not allowed for column "REV"
I'm trying to add an auto_increment to my Liquibase changelog file.

Answer 1

You can use the SQL Standard's generation clause GENERATED ALWAYS AS IDENTITY. For example:
create table test (
id bigint generated always as identity,
name varchar(10)
);
See PostgreSQL Example.
It works the same way in H2. For example:
create table test(id bigint generated always as identity, name varchar(10));
insert into test (name) values ('Chicago') ;
select * from test;
Result:
ID NAME
-- -------
1 Chicago