修复findByPid方法

src/main/java/edu/math/diagnosis/service/PaperCountService.java

@@ -13,6 +13,6 @@ public class PaperCountService {
     private PaperCountRepo paperCountRepo;
 
      public PaperCount findByPid(Long pid){
-
+        return paperCountRepo.findByPid(pid);
      }
 }