Cannot populate database with liquibase

I'm building a small spring-boot application. I'm using spring-data-jpa to create the database schema and liquibase to populate it with test data.

application.properties:

spring.datasource.url=jdbc:postgresql://localhost:5432/book-db
spring.datasource.driver-class-name=org.postgresql.Driver

spring.datasource.username=admin
spring.datasource.password=lTIDDYz3n3jD3BeYaAJz
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=create
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true

According to the documentation no configuration for liquibase is required if I have a gradle dependency and master changeLog under the default path.

db.changelog-master.yaml:

databaseChangeLog:
      - changeSet:
            id: 1
            author: jb
            changes:
            - sqlFile:
                  path: db/migration/insert-books.sql

insert-books.sql:

--liquibase formatted sql
--changeset admin:1
delete from book;
insert into book (id, title)
values (nextval('seq'), 'Functional Programming for Mortals');
commit;

I have tried it with and without commit. The tables databasechangelog and databasechangelog are created successfully and contain the migration (insert-books).

The migration goes through, because if I add an invalid insert (to some table that does not exist), I get the exception:

ERROR: relation "xxx" does not exist

How to populate the database with data in insert-books.sql script using liquibase?

Don't use both, liquibase and JPA, to manage the DB structure. If you want to use liquibase, set JPA (Hibernate) to just validate the schema and manage the schema within liquibase.

spring.jpa.hibernate.ddl-auto=validate

The problem with your solution is in the order of operations. When your application starts, it first runs liquibase, which inserts the data, then JPA is started and the schema is created from scratch.

Try dropping the schema before running the app, I bet the migration (liquibase) will fail.

Liquibase has to be in charge of the schema, there is a way to add liquibase to an existing database, but it again makes liquibase the owner of the schema:

https://stackoverflow.com/questions/16455624/using-liquibase-on-the-existing-database