Spring POST Method Microservice 500 exception

So, im trying to write a microservice with basic GET POST PUT DELETE commands. Its a Spring Maven Java programm with a mysql server

When I try to post something it works, however if I dont include the Id it returns an exception:

"status": 500,
  "error": "Internal Server Error",
  "message": "could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement",

This is weird, because in the mysql console I can Insert a customer without the id, it just autoincrements. Also null works too. Posting however with the Id being null doesn’t work

Here some pieces of my code:

@Service
public class CustomerService {

    private final CustomerRepository customerRepository;

    @Autowired
    public CustomerService(CustomerRepository customerRepository) {
        this.customerRepository = customerRepository;
    }

    public List<Customer> getCostumer() {
        return customerRepository.findAll();
    }

    public void addNewCustomer(Customer customer) {
        customerRepository.save(customer);
        System.out.println(customer);
    }

    public void deleteCustomer(Long customerId) {
        if (!customerRepository.existsById(customerId)) {
            throw new IllegalStateException("customer with id " +customerId+ " does not exist");
        }
        customerRepository.deleteById(customerId);
    }
}

@RestController
@RequestMapping(path = "api/v1/customer")
public class CustomerController {

    private final CustomerService customerService;

    @Autowired
    public CustomerController(CustomerService customerService) {
        this.customerService = customerService;
    }

    @GetMapping
    public List<Customer> getCostumer() {
        return customerService.getCostumer();
    }

    @PostMapping
    public void registerNewCustomer(@RequestBody Customer customer) {
        customerService.addNewCustomer(customer);
    }

    @DeleteMapping(path = "{customerId}")
    public void deleteCustomer(@PathVariable("customerId") Long customerId) {
        customerService.deleteCustomer(customerId);
    }
}

@Repository
public interface CustomerRepository extends JpaRepository<Customer, Long> {

    Optional<Customer> findCustomerById(Long id);
}


@Entity
@Table
public class Customer {
    @Id
    private String name;
    private String contactFirstName;
    private String contactLastName;
    private String phoneNumber;
    private String fax;
    private String city;
    private String region;
    private String country;
    private String zip;
    private float creditLimit;
    private String adress_1;
    private String adress_2;
    private Long id;

    public Customer() {
    }

    public Customer(String name, String contactFirstName, String contactLastName, String phoneNumber, String fax, String city, String region, String country, String zip, float creditLimit, String adress_1, String adress_2, Long id) {
        this.name = name;
        this.contactFirstName = contactFirstName;
        this.contactLastName = contactLastName;
        this.phoneNumber = phoneNumber;
        this.fax = fax;
        this.city = city;
        this.region = region;
        this.country = country;
        this.zip = zip;
        this.creditLimit = creditLimit;
        this.adress_1 = adress_1;
        this.adress_2 = adress_2;
        this.id = id;
    }

    public Customer(String name, String contactFirstName, String contactLastName, String phoneNumber, String fax, String city, String region, String country, String zip, float creditLimit, String adress_1, String adress_2) {
        this.name = name;
        this.contactFirstName = contactFirstName;
        this.contactLastName = contactLastName;
        this.phoneNumber = phoneNumber;
        this.fax = fax;
        this.city = city;
        this.region = region;
        this.country = country;
        this.zip = zip;
        this.creditLimit = creditLimit;
        this.adress_1 = adress_1;
        this.adress_2 = adress_2;
    }
//the rest of the code is just getters and setters

SOLVED solution is:

@Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id",unique=true, nullable = false)
    private Long id;

thanks guys!

Answer

Your model points out that name is the primary key, but it seems like your database model has the id beeing the primary key with probably auto_increment assigned to it.

You should adjust your model accordingly, eg like this:

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

I’m not sure what strategy is correct with MySQL, but this may help.

If you have a constraint on your name column to be unique you could add an according annotation to it, like this:

@Column(unique = true)
private String name;