Springboot如何根据实体类生成数据库表

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
       </dependency>
        <dependency>
            <groupId>Mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

server:
  port: 8001
spring:
  application:
    name: jih-manage
  datasource:
    name: test
    url: jdbc:mysql://111.231.231.56/jih
    username: root
    passWord: root
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

spring:
    datasource:
        driver-class-name:  com.mysql.jdbc.Driver
        url: jdbc:mysql://127.0.0.1:3306/facemap
        username: root
        password: root
    jpa:
        hibernate:
            ddl-auto: update
            show-sql: true

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/dbgirl?characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=root
spring.jpa.show-sql= true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
spring.jackson.serialization.indent_output=false

package com.example.demo;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
@Entity //实体类的注解
public class Girl {
    @Id //@id注意选择这个javax.persistence
    @GeneratedValue
    private  Integer  id;
    private  String   cupSize;
    private  Integer   age;
    public Girl() {
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getCupSize() {
        return cupSize;
    }
    public void setCupSize(String cupSize) {
        this.cupSize = cupSize;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
}

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-WEB</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
 
        <!--mysql-connection-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
 
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

server:
  port: 8080
 
spring:
  datasource:
    type: com.zaxxer.hikari.HikariDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/h5mall?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: 123456
    hikari:
      minimum-idle: 5
      idle-timeout: 180000
      maximum-pool-size: 10
      auto-commit: true
      pool-name: MyHikariCP
      connection-timeout: 30000
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

 
import javax.persistence.*; 
@Entity
@Table(name = "user")
@Data
public class User {
 
    @Id
    @GeneratedValue
    private Long id;
 
    //name属性为表的字段名。length为字段的长度
    @Column(length = 30, name = "userId")
    private String userId;
 
    @Column(name = "userName", length = 20, columnDefinition="varchar(100) COMMENT '用户名'")
    private String userName;
 
    @Column(name = "phone", length = 20)
    private String phone;
 
    @Column(name = "password", length = 30)
    private String password;
 
    @Column(name = "userRealName", length = 20)
    private String userRealName;
 
    @Column(name = "address", length = 20)
    private String address;
}