使用JPA重构DAO层

src/main/java/com/example/springdemo/dao/MerchantsRepository.java

@@ -1,14 +1,12 @@
 package com.example.springdemo.dao;
 
 import com.example.springdemo.entities.Merchants;
-import org.jetbrains.annotations.NotNull;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
-import java.util.List;
-
 @Repository
-public interface MerchantsRepository extends JpaRepository<Merchants, Long> {
-    List<Merchants> findByName(String name);
-    void deleteById(@NotNull Long id);
+public interface MerchantsRepository
+        extends JpaRepository<Merchants, Long> {
+    Merchants findByName(String name);
+
 }

src/main/java/com/example/springdemo/dao/UsersRepository.java

@@ -0,0 +1,11 @@
+package com.example.springdemo.dao;
+
+import com.example.springdemo.entities.Users;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UsersRepository
+        extends JpaRepository<Users, Long> {
+    Users findByName(String name);
+}