diff --git a/spring-data-jpa-1/initial/src/main/java/cholog/Customer.java b/spring-data-jpa-1/initial/src/main/java/cholog/Customer.java
index 492197fc..1720c42c 100644
--- a/spring-data-jpa-1/initial/src/main/java/cholog/Customer.java
+++ b/spring-data-jpa-1/initial/src/main/java/cholog/Customer.java
@@ -1,7 +1,14 @@
 package cholog;
 
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+
+@Entity
 public class Customer {
 
+    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String firstName;
     private String lastName;
diff --git a/spring-data-jpa-1/initial/src/main/java/cholog/CustomerRepository.java b/spring-data-jpa-1/initial/src/main/java/cholog/CustomerRepository.java
index 879c8fe8..fde49359 100644
--- a/spring-data-jpa-1/initial/src/main/java/cholog/CustomerRepository.java
+++ b/spring-data-jpa-1/initial/src/main/java/cholog/CustomerRepository.java
@@ -1,5 +1,16 @@
 package cholog;
 
-public interface CustomerRepository {
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
 
+import java.util.List;
+
+@Repository
+public interface CustomerRepository extends CrudRepository<Customer, Long> {
+
+    List<Customer> findByLastName(String lastName);
+
+    List<Customer> findByLastNameIgnoreCase(String lastName);
+
+    List<Customer> findByLastNameOrderByFirstNameDesc(String lastName);
 }
diff --git a/spring-data-jpa-1/initial/src/test/java/cholog/EntityManagerTest.java b/spring-data-jpa-1/initial/src/test/java/cholog/EntityManagerTest.java
index 7fbc3638..68238b74 100644
--- a/spring-data-jpa-1/initial/src/test/java/cholog/EntityManagerTest.java
+++ b/spring-data-jpa-1/initial/src/test/java/cholog/EntityManagerTest.java
@@ -17,6 +17,8 @@ public class EntityManagerTest {
 
     @Autowired
     private JdbcTemplate jdbcTemplate;
+    @Autowired
+    private CustomerRepository customerRepository;
 
     /**
      * 비영속 -> 영속
@@ -34,12 +36,12 @@ void persist() {
      */
     @Test
     void flush() {
-        String sqlForSelectCustomer = "select * from customer where id = 1";
-
         Customer customer = new Customer("Jack", "Bauer");
         entityManager.persist(customer);
         customer.updateFirstName("Danial");
 
+        String sqlForSelectCustomer = "select * from customer where id = " + customer.getId();
+
         Customer savedCustomer = jdbcTemplate.query(sqlForSelectCustomer, rs -> {
             rs.next();
             return new Customer(