项目启动就报错：
[ERROR][2020-09-02 11:33:38][org.springframework.boot.SpringApplication.reportFailure(SpringApplication.java:826)] Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘YYZXController’: Unsatisfied dependency expressed through field ‘yyzxService’; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘YYZXRWJHServiceImpl’: Unsatisfied dependency expressed through field ‘yyzxDao’; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘YYZXRWJHDao’ defined in URL [jar:file:/C:/Users/Administrator/Desktop/demo2/demo-module57/57v1/grgt_savant-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/com/example/demo/mapper/YYZXRWJHDao.class]: Unsatisfied dependency expressed through bean property ‘sqlSessionFactory’; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘sqlSessionFactory’ defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method ‘sqlSessionFactory’ threw exception; nested exception is org.apache.ibatis.type.TypeException: The alias ‘OAOrderFactBill’ is already mapped to the value ‘com.example.demo.entity.sly.mdxx.OAOrderFactBill’.

原因：配置文件中要扫描的包有重复类

在我这里com.example.demo.entity包下的各子包分别定义了具有重复名字的类，导致扫描时出错。

解决方案：修改具有重复名字的类。这是我选择的方案。