Unsatisfied dependency expressed through field 'repositoryService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repositoryServiceBean' defined in class path resource [org/activiti/spring/boot/ProcessEngineAutoConfiguration.class]: Unsatisfied dependency expressed through method 'repositoryServiceBean' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processEngine': FactoryBean threw exception on object creation; nested exception is org.activiti.engine.ActivitiException: couldn't deduct database type from database product name 'MySql'

这个错误通常是由于 Activiti 的自动配置引起的。它试图通过检查数据库类型来配置 Activiti，但在这种情况下，它无法推断出数据库类型。解决此问题的一种方法是手动配置 Activiti 数据库。你可以在 application.properties 或 application.yml 文件中指定 Activiti 数据库类型、驱动程序类和连接 URL，例如：

spring.activiti.database-type=mysql
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/activiti
spring.datasource.username=your-username
spring.datasource.password=your-password

如果你已经手动配置了 Activiti 数据库，那么可能是由于依赖项不正确导致的。你可以检查一下你的依赖项是否正确，或者尝试更新 Activiti 版本。