[EDIT]AllocationRepositoryにcategoryId取得の作成

src/main/java/com/example/demo/app/infra/repository/AllocationRepository.java

@@ -1,10 +1,12 @@
 package com.example.demo.app.infra.repository;
 
+import java.util.List;
+
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import com.example.demo.app.infra.entity.AllocationEntity;
 
 public interface AllocationRepository extends JpaRepository<AllocationEntity, Long>{
 	
-	
+	List<AllocationEntity> findByCourseId(Long courseId);
 }