内存数据库 H2 中的 Spring Boot 在初始化时不会从文件加载数据

Question

I have an issue with loading data into an in-memory database on application initialization. I have created schema.sql and data.sql files containing table structure and initial data.

schema.sql :

CREATE TABLE users (
  id          INT PRIMARY KEY,
  username    VARCHAR(64) NOT NULL,
  password    VARCHAR(64) 
);

and data.sql :

INSERT INTO users (id, username, password) VALUES
  (1, 'usr1', 'bigSecret'),
  (2, 'usr2', 'topSecret');

I am using JpaRepository for working with data layer:

public interface UserRepository extends JpaRepository<User, Long> {
}

And I also configure application.properties

spring.datasource.initialize=true
spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=- 1;DB_CLOSE_ON_EXIT=FALSE
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=

But when I call

List<User> users = userRepository.findAll();

User entity

@Entity
@Table(name = "users")
public class User {

  @Id
  @GeneratedValue
  private Long id;
  private String username;
  private String password;

  public User() {  }

  public Long getId() {
    return id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public String getUsername() {
    return username;
  }

  public void setUsername(String username) {
    this.username = username;
  }

  public String getPassword() {
    return password;
  }

  public void setPassword(String password) {
    this.password = password;
  }
}

I get an empty list, but I should get two pre-populated users from my in-memory H2 database. What's wrong with in memory database? Thanks.

Answer 1

You can always try to run those scripts per specification of h2, where you should add an INIT script in your connection url (being one of the options):

jdbc:h2:mem:test;INIT=RUNSCRIPT FROM '~/schema.sql'\;RUNSCRIPT FROM '~/data.sql'"

This functionality is enabled via the INIT property. Note that multiple commands may be passed to INIT, but the semicolon delimiter must be escaped, as in the example below.

Update

Be aware that having these options in your application.properties :

spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=true
spring.datasource.initialize=true

may cause some clashing during startup. So you should always aim for one or the other, but never both at the same time. For simple cases just these alone are sufficient to auto build tables and reload after shutdown & startup

Answer 2

I solved a similar problem when I added the following lines to the application.properties:

spring.jpa.hibernate.ddl-auto=none
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true
spring.session.jdbc.initialize-schema=always
spring.sql.init.data-locations=classpath:schema.sql,classpath:data.sql