对于许多应用程序，我们需要做的就是安装正确的弹簧
classpath.it上的数据依赖关系很好：
配置：
@Configuration
@EnableAutoConfiguration
@EntityScan(basePackages = {"io.boot.spring.entities"})
@EnableJpaRepositories(basePackages = {"io.boot.spring.repositories"})
@EnableTransactionManagement
public class ConfigForJPA {
@Bean
@ConfigurationProperties("spring.datasource.hikari")
public HikariDataSource dataSource() {
return (HikariDataSource) DataSourceBuilder.create()
.type(HikariDataSource.class).build();
}
}
application.properties：
spring.datasource.hikari.jdbc-url=jdbc:h2:mem:mydb
spring.datasource.hikari.username=sa
spring.datasource.hikari.password=
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true
spring.jpa.hibernate.use-new-id-generator-mappings=true
安慰：
Hibernate: drop table Blog if exists
Hibernate: drop table Item if exists
Hibernate: drop table Role if exists
Hibernate: drop table User if exists
Hibernate: drop table User_roles if exists
Hibernate: drop sequence if exists hibernate_sequence
Hibernate: create sequence hibernate_sequence start with 1 increment by 1
Hibernate: create table Blog
Hibernate: create table Item
Hibernate: create table Role
Hibernate: create table User
Hibernate: create table User_roles (users_id integer not null, roles_id integer not null)
main] org.hibernate.tool.hbm2ddl.SchemaExport : HHH000230: Schema export complete
j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
Hibernate: call next value for hibernate_sequence
Hibernate: insert into Role (name, id) values (?, ?)
Hibernate: call next value for hibernate_sequence
Hibernate: insert into Role (name, id) values (?, ?)
Hibernate: call next value for hibernate_sequence
Hibernate: insert into User (email, name, password, id) values (?, ?, ?, ?)
Hibernate: insert into User_roles (users_id, roles_id) values (?, ?)
Hibernate: insert into User_roles (users_id, roles_id) values (?, ?)
但是Spring Boot Doc说要完全控制
EntityManagerFactory，您需要添加一个名为“ entityManagerFactory”的@Bean
并将其添加到我的配置中。
配置：
@Bean
public LocalContainerEntityManagerFactoryBean
entityManagerFactory(EntityManagerFactoryBuilder builder) {
return builder
.dataSource(dataSource())
.packages("io.boot.spring")
.persistenceUnit("io.boot.spring.entities")
.build();
}
它给出了错误：
安慰：
: HHH000412: Hibernate Core {5.0.11.Final}
: HHH000206: hibernate.properties not found
: HHH000021: Bytecode provider name : javassist
: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Started.
: HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory
for persistence unit 'io.boot.spring.entities'
Hibernate: call next value for hibernate_sequence
: SQL Error: 90036, SQLState: 90036
: Sequence "HIBERNATE_SEQUENCE" not found; SQL statement:
call next value for hibernate_sequence [90036-193]
为什么找不到HIBERNATE_SEQUENCE？我没有修改任何东西
刚刚将entityManagerFactory bean添加到配置文件
实体：
@Entity
public class Role {
@Id
@GeneratedValue(strategy=GenerationType.SEQUENCE)
private Integer id;
private String name;
... getters and setters
最佳答案
解决方法是：
CREATE TABLE CLIENT(
ID INTEGER NOT NULL,
CLIENT_NAME VARCHAR(255) NOT NULL,
ACTIVE CHAR(1) NOT NULL DEFAULT 'Y'
);
CREATE SEQUENCE CLIENT_SEQUENCE_ID START WITH (select max(ID) + 1 from CLIENT);
（这允许您使用静态值预填充客户端，并相应地初始化序列）
和在Java中
@Id
@SequenceGenerator(name= "CLIENT_SEQUENCE", sequenceName = "CLIENT_SEQUENCE_ID", initialValue=1, allocationSize = 1)
@GeneratedValue(strategy=GenerationType.AUTO, generator="CLIENT_SEQUENCE")
private Long id
;
请按照以上说明进行操作。