如何使用Spring Boot连接到H2数据库？

Question

我是Spring Boot的新手，正在尝试创建一个API，该API将用于获取有关员工的信息。 在我的application.properties文件中，我有：

spring.datasource.url=jdbc:h2:mem:employees

在data.sql中，我有：

INSERT INTO employees(name, age) VALUES ( 'PersonOne', 39 );
INSERT INTO employees(name, age) VALUES ( 'PersonTwo', 23 );
INSERT INTO employees(name, age) VALUES ( 'PersonThree', 45 );

COMMIT;

然后，我创建了一个RestRepository接口：

package com.example.demo;

import org.springframework.data.repository.CrudRepository;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;

@RepositoryRestResource
public interface RestRepository extends CrudRepository<Employee, Long> {

}

还有一个Employee类，其中包含以下字段以及一些getter和setter：

@Entity
public class Employee {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    private String name;
    private Double age;

    *some getters and setters*

但是我一直收到错误消息：创建名称为'entityManagerFactory'的bean时出错

编辑：整个错误堆栈跟踪为：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Initialization of bean failed; nested exception is org.springframework.jdbc.datasource.init.ScriptStatementFailedException: Failed to execute SQL script statement #1 of URL [file:/Users/noratomas/Documents/Tutorials/Spring%20Boot/demo/target/classes/data.sql]: INSERT INTO employees(name, age) VALUES ( 'PEersonOne', 39 ); nested exception is org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "EMPLOYEES" not found; SQL statement:
INSERT INTO employees(name, age) VALUES ( 'PersonOne', 39 ) [42102-199]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at com.example.demo.DemoApplication.main(DemoApplication.java:10) ~[classes/:na]
Caused by: org.springframework.jdbc.datasource.init.ScriptStatementFailedException: Failed to execute SQL script statement #1 of URL [file:/Users/noratomas/Documents/Tutorials/Spring%20Boot/demo/target/classes/data.sql]: INSERT INTO employees(name, age) VALUES ( 'PersonOne', 39 ); nested exception is org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "EMPLOYEES" not found; SQL statement:
INSERT INTO employees(name, age) VALUES ( 'PersonOne', 39 ) [42102-199]
    at org.springframework.jdbc.datasource.init.ScriptUtils.executeSqlScript(ScriptUtils.java:509) ~[spring-jdbc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.jdbc.datasource.init.ResourceDatabasePopulator.populate(ResourceDatabasePopulator.java:238) ~[spring-jdbc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.jdbc.datasource.init.DatabasePopulatorUtils.execute(DatabasePopulatorUtils.java:48) ~[spring-jdbc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.runScripts(DataSourceInitializer.java:202) ~[spring-boot-autoconfigure-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.initSchema(DataSourceInitializer.java:119) ~[spring-boot-autoconfigure-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker.onApplicationEvent(DataSourceInitializerInvoker.java:89) ~[spring-boot-autoconfigure-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker.onApplicationEvent(DataSourceInitializerInvoker.java:37) ~[spring-boot-autoconfigure-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.DataSourceInitializedPublisher.publishEventIfRequired(DataSourceInitializedPublisher.java:94) ~[spring-boot-autoconfigure-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.DataSourceInitializedPublisher.postProcessAfterInitialization(DataSourceInitializedPublisher.java:85) ~[spring-boot-autoconfigure-2.1.7.RELEASE.jar:2.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:429) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    ... 15 common frames omitted
Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "EMPLOYEES" not found; SQL statement:
INSERT INTO employees(name, age) VALUES ( 'PersonOne', 39 ) [42102-199]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:451) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:427) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.message.DbException.get(DbException.java:205) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.message.DbException.get(DbException.java:181) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.readTableOrView(Parser.java:7146) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.readTableOrView(Parser.java:7117) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.parseInsert(Parser.java:1682) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.parsePrepared(Parser.java:891) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.parse(Parser.java:788) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.parse(Parser.java:760) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.command.Parser.prepareCommand(Parser.java:683) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.engine.Session.prepareLocal(Session.java:627) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.engine.Session.prepareCommand(Session.java:565) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1292) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:217) ~[h2-1.4.199.jar:1.4.199]
    at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:205) ~[h2-1.4.199.jar:1.4.199]
    at com.zaxxer.hikari.pool.ProxyStatement.execute(ProxyStatement.java:95) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.pool.HikariProxyStatement.execute(HikariProxyStatement.java) ~[HikariCP-3.2.0.jar:na]
    at org.springframework.jdbc.datasource.init.ScriptUtils.executeSqlScript(ScriptUtils.java:488) ~[spring-jdbc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    ... 31 common frames omitted

有什么事吗

Answer 1

查看堆栈跟踪，看起来您的表不存在。 在向其中插入数据之前，应该先有一个表。 创建一个scheme.sql并在其中创建您的Employee表。 如果您使用的是H2数据库，也可以直接从Employee类文件在内部创建它。

Answer 2

问题是您要插入数据的表称为EMPLOYEES（带有“ S”），而您的实体称为Employee。

Spring Boot可能正在为您创建该表，但没有“ S”。

尝试更改您的INSERT语句。

Answer 3

您是否在SQL中创建了表？ 如果不是，则应该为每个实体手动创建表，或者使用以下命令简单地启用自动DDL： spring.jpa.hibernate.ddl-auto

Answer 4

Hibernate DDL将要从您的实体生成的表将被命名为Employee而不是Employees

Answer 5

您要插入EMPLOYEE S ，而您的实体称为EMPLOYEE。

如果您希望Hibernate创建EMPLOYEE S ，则可以在Employee类的顶部添加@Table批注。

@Entity
@Table(name = "EMPLOYEES")
public class Employee