spring-framework-repository

1. Create Models named Customer and CustomerType

@Entity
@AllArgsConstructor
@NoArgsConstructor
@Data
public class Customer {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  public int id;
  public String customerName;

  @OneToOne
  @JoinColumn(name = "customerType", referencedColumnName = "id")
  public CustomerType customerType;
}

@Entity
@AllArgsConstructor
@NoArgsConstructor
@Data
public class CustomerType {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  public int id;
  public String customerTypeName;
}

2. Create Repository

@Repository
public interface CustomerRepository extends CrudRepository<Customer, Integer> {
  // ...
}

3. Write Function in CustomerRepository

WHERE CustomerName = "Furkan"

 public List<Tunnel> findByCustomerName(String customerName);

WHERE CustomerName = "Furkan" AND CustomerType.CustomerTypeId = 1

 public List<Tunnel> findByCustomerNameAndCustomerTypeId(String customerName, int customerType);

WHERE CustomerName = "Furkan" AND CustomerType.CustomerTypeId = 1

 public List<Tunnel> findByCustomerNameAndCustomerType(String customerName, CustomerType customerType);

SELECT * FROM Customer WHERE CustomerType = XXX

 @Query("SELECT t FROM Customer t WHERE t.customerType = :customerType")
 Optional<Iterable<Customer>> select(@Param("customerType") Optional<CustomerType> customerType);