书上说的是mariadb，直接连mysql是可以的。但改成mysql了，报错了，作了一下调整。

一，pom.xml配置

org.springframework.boot

spring-boot-starter-web

org.springframework.boot

spring-boot-starter-data-jpa

com.h2database

h2

runtime

mysql

mysql-connector-java

runtime

org.springframework.boot

spring-boot-devtools

runtime

true

org.springframework.boot

spring-boot-starter-test

test

org.junit.vintage

junit-vintage-engine

二，建立实体(包含一对多和多对一)

Car.java

package com.packt.cardatabase.domain;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.ManyToOne;

import javax.persistence.FetchType;

@Entity

public class Car {

@Id

@GeneratedValue(strategy=GenerationType.AUTO)

private long id;

private String brand, model, color, registerNumber;

private int year, price;

@ManyToOne(fetch = FetchType.LAZY)

@JoinColumn(name = "owner")

private Owner owner;

public Car() {

}

public Car(String brand, String model, String color, String registerNumber, int year, int price, Owner owner) {

super();

this.brand = brand;

this.model = model;

this.color = color;

this.registerNumber = registerNumber;

this.year = year;

this.price = price;

this.owner = owner;

}

public String getBrand() {

return brand;

}

public String getModel() {

return model;

}

public String getColor() {

return color;

}

public String getRegisterNumber() {

return registerNumber;

}

public int getYear() {

return year;

}

public int getPrice() {

return price;

}

public Owner getOwner() {

return owner;

}

public void setBrand(String brand) {

this.brand = brand;

}

public void setModel(String model) {

this.model = model;

}

public void setColor(String color) {

this.color = color;

}

public void setRegisterNumber(String registerNumber) {

this.registerNumber = registerNumber;

}

public void setYear(int year) {

this.year = year;

}

public void setPrice(int price) {

this.price = price;

}

public void setOwner(Owner owner) {

this.owner = owner;

}

}

Owner.java

package com.packt.cardatabase.domain;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.OneToMany;

import javax.persistence.CascadeType;

import java.util.List;

@Entity

public class Owner {

@Id

@GeneratedValue(strategy = GenerationType.AUTO)

private long ownerId;

private String firstname, lastname;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner")

private List cars;

public Owner() {

}

public Owner(String firstname, String lastname) {

super();

this.firstname = firstname;

this.lastname = lastname;

}

public long getOwnerId() {

return ownerId;

}

public String getFirstname() {

return firstname;

}

public String getLastname() {

return lastname;

}

public List getCars() {

return cars;

}

public void setOwnerId(long ownerId) {

this.ownerId = ownerId;

}

public void setFirstname(String firstname) {

this.firstname = firstname;

}

public void setLastname(String lastname) {

this.lastname = lastname;

}

public void setCars(List cars) {

this.cars = cars;

}

}

三，建立repository接口

CarRepository.java

package com.packt.cardatabase.domain;

import org.springframework.data.repository.CrudRepository;

public interface CarRepository extends CrudRepository {

}

OwnerRepository.java

package com.packt.cardatabase.domain;

import org.springframework.data.repository.CrudRepository;

public interface OwnerRepository extends CrudRepository{

}

四，application.properties配置

logging.level.root=INFO

server.port=8080

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

spring.datasource.url=jdbc:mysql://localhost:3306/cardb?serverTimezone=GMT%2B8

spring.datasource.username=root

spring.datasource.password=password

spring.jpa.generate-ddl=true

spring.jpa.properties.hibernate.hbm2ddl.auto=create-drop

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect

spring.jpa.show-sql= true

五，建立数据库

mysql下，略过不表

六，运行测试

2020-10-08 21_57_50-mvnw.png

2020-10-08 21_58_32-car @cardb (localhost3306) - 表 - Navicat for MySQL.png