update

src/demo/src/main/java/com/example/demo/DemoApplication.java

@@ -7,7 +7,7 @@ import org.springframework.context.annotation.ComponentScan;
 
 @SpringBootApplication
 
-@ComponentScan(basePackages = {"com.example.demo.controller", "com.example.demo.config", "com.example.demo.service.impl"})
+@ComponentScan(basePackages = {"com.example.demo.controller", "com.example.demo.config", "com.example.demo.service.impl","com.example.demo.mapper"})
 @MapperScan("com.example.demo.mapper")
 
 public class DemoApplication {