SpringBoot连接mysql需要在application.properties添加一些微调信息，Spring自带连接池，如果用Spring自带的连接池：
spring.datasource.url=jdbc:mysql://localhost:3306/jelly?useSSL=false&characterEncoding=utf8
spring.datasource.username=tom
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
然后配置Hibernate
# Specify the DBMSspring.jpa.database=MYSQL# Show or not log for each sql queryspring.jpa.show-sql=true# Hibernate ddl auto (create, create-drop, update)spring.jpa.hibernate.ddl-auto=update# Naming strategyspring.jpa.hibernate.naming-strategy=org.hibernate.cfg.ImprovedNamingStrategy# stripped before adding them to the entity manager)
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
