我应该如何使用SpringBoot创建H2？

Question

我开始玩Spring Boot,作为其中的一部分,我想创建一个内存DB来与应用程序一起工作和引导程序.

鉴于下面的配置/代码我在启动日志中没有错误并且可以访问应用程序,所以它确实启动(我得到关于不存在的对象的模板错误),但是在调用时我没有从DAO获得任何数据findAll()(或者如果我尝试调用findById(int)).

所以虽然看起来一切正常(日志中没有错误,日志显示它找到sql来创建架构广告尝试运行data.sql语句)当我尝试通过DAO访问数据时我没有得到异常,但没有返回数据.

关于代码可能有问题的任何想法或观察？

我已将Spring Data/H2添加到我的pom中:

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
    </dependency>

春天DAO:

public interface PersonDao extends CrudRepository<Person, Integer> {
}

application.properties中的数据库道具:

server.contextPath=/
server.port=8080
spring.mvc.view.suffix=.ftl

datasource.mine.jdbcUrl=jdbc:h2:tcp://localhost/mem:clubmanagement
datasource.mine.user=sa
datasource.mine.password=
datasource.mine.poolSize=30

logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate=DEBUG

spring.jpa.hibernate.ddl-auto=create

我的服务:

@Service
public class MemberServiceImpl implements MemberService {

@Autowired
PersonDao dao;

@Override
public Optional<ClubMember> getClubMember(int id) {
    Person dbPerson = dao.findOne(id);
    if(dbPerson == null) {
        return Optional.empty();
    }
    return Optional.of(fromEntity(dbPerson));
}

@Override
public List<ClubMember> allMembers() {
    Iterable<Person> people = dao.findAll();
    List<ClubMember> members = new ArrayList<>();
    people.forEach(person -> {
        members.add(fromEntity(person));
    });
    return members;
}

private ClubMember fromEntity(Person p) {
    ClubMember member = new ClubMember();
    member.setCurrentGrade(p.getCurrentGrade());
    member.setFirstName(p.getFirstName());
    member.setLastName(p.getLastName());
    member.setAssociationMemberId(p.getAssociationMemberId());
    member.setLastGradingDate(p.getLastGradingDate());
    return member;
}
}

资源中的Schema.sql /:

create table CLUB
  (id int not null, name varchar(60), association_member_id int);

create table PERSON
(
id int not null, grade_id int, first_name varchar(35), last_name varchar(35),
association_membership varchar(12), last_grading_date date
);

create table GRADE
  (id int not null, name varchar(20));

在data.sql中(再次在资源目录中):

insert into club (id, name, association_member_id) values (1, 'some club', '123');

insert into person (id, grade_id, first_name, last_name, association_membership, last_grading_date)
values (1, 1, 'name', 'lastname', 'a1234', '2016-03-23');

我试图检索的实体类(尝试使用Lombock,对我来说也是新的,以生成getter/setter):

@Entity
@Table(name = "person")
public @Data class Person {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "id")
private int id;

@JoinColumn(name = "grade_id")
private GRADE currentGrade;

@Column(name = "first_name")
private String firstName;

@Column(name = "last_name")
private String lastName;

@Column(name = "association_membership")
private String associationMemberId;

@Column(name = "last_grading_date")
@Temporal(value = TemporalType.DATE)
private Date lastGradingDate;
}

Answer 1

你想添加H2数据库,但你添加了HSQLDB,请替换

<dependency>
        <groupId>org.hsqldb</groupId>
        <artifactId>hsqldb</artifactId>
        <scope>runtime</scope>
    </dependency>

同

<dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>

编辑

我注意到您的代码中存在多个问题:

1. 默认模式文件名是schema.sql而不是Schema.sql
2. schema.sql中表的名称与data.sql中的名称不同(PERSON与person)
3. 你spring.jpa.hibernate.ddl-auto=create在application.properties(默认选项)中使用过这个,在这种情况下,JPA数据库模式只会自动创建(没有数据创建),所以不会执行data.sql,修复你可以使用的选项validate或update选项

我将写一个简单的例子,说明如何使用带有spring boot和JPA的H2数据库

这是项目结构:

等级实体

package com.shijazi;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="GRADE")
public class Grade {

    @Id
    @GeneratedValue
    private int id;

    private String name;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Grade(int id, String name) {
        super();
        this.id = id;
        this.name = name;
    }
    public Grade() {
    }



}

GradeRepository.java

package com.shijazi;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;


@Repository
public interface GradeRepository extends JpaRepository<Grade, Integer> {

}

Application.java

@SpringBootApplication
@RestController
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Autowired
    private GradeRepository gradeRepo;

    @RequestMapping(value="api/test")
    public List<Grade> getall()
    {
        return  gradeRepo.findAll();
    }
}

application.properties

spring.jpa.hibernate.ddl-auto=validate

schema.sql文件

create table GRADE (id int not null, name varchar(20));

data.sql

insert into GRADE (id, name) values (2,  'name');

pom.xml中的依赖项

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>

现在只需运行应用程序并调用此URL: http://localhost:8080/api/test

尝试更改spring.jpa.hibernate.ddl-auto并查看结果

如果你激活ddl-auto并且有一个schema.sql,那么它们就会被执行.但通常先执行schema.sql.所以ddl-auto抛出一切,这是由schema.sql和data.sql创建的