报错 'ddlApplicationRunner' is expected to be of type 'org.springframework.boot.Runner' but was actually of type 'org.springframework.beans.factory.support.NullBean'

是由于版本问题，将spring-boot-starter-parent从3.3.3降为3.2.2同时将mybatis-spring-boot-starter升级到最新的3.0.3即可