Dao层实现

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

@@ -0,0 +1,15 @@
+package com.example.springdemo.dao;
+
+import com.example.springdemo.entities.Merchants;
+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(Long id);
+}

src/main/java/com/example/springdemo/dao/package-info.java

@@ -0,0 +1,4 @@
+@NonNullApi
+package com.example.springdemo.dao;
+
+import org.springframework.lang.NonNullApi;