spring:
  datasource:
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/demo
    driver-class-name: com.mysql.jdbc.Driver
  jpa:
    hibernate:
      ddl-auto: update
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
    show-sql: true
server:
  port: 8090

数据库引擎问题,加上就ok了