I'm just trying to create post api in database but it's not working and give an error :

ERROR: null value in column "first_name" of relation "customer" violates not-null constraint Detail: Failing row contains (24, 0, null, null, [email protected], null, f).

This is my API:

@PostMapping("/customers")
    public ResponseEntity<Customer> createCustomer(@RequestBody Customer customer) {
        try {
            Customer _customer = cutomerRepository
                    .save(new Customer(customer.getSerialNumber(), customer.getFirstName(),customer.getLastName(),customer.getEmail(),customer.getMobileNumber()));
            return new ResponseEntity<>(_customer, HttpStatus.CREATED);
        } catch (Exception e) {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

This my customer model:

@Entity
@Table(name = "customer")

    public class Customer {
        @Id
        @GeneratedValue(strategy= GenerationType.IDENTITY)
        private int id;
        @Column(name = "serial_number")
        private long serialNumber;
        @Column(name = "first_name")
        private String firstName;
        @Column(name = "last_name")
        private String lastName;
        @Column(name = "email")
        private String email;
    @Column(name = "mobile_number")
    private String mobileNumber;
    @Column(name = "is_deleted")
    private boolean isDeleted;


    @OneToMany
    private Set <Invoice> invoices;

    public Customer(){}
    public Customer(long serialNumber , String firstName, String lastName, String email, String mobileNumber) {
        this.serialNumber = serialNumber;
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
        this.mobileNumber = mobileNumber;
        this.isDeleted = false;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public int getId() {
        return this.id;
    }
    public String getName() {
        return this.firstName;
    }
    public Long getSerialNumber() {
        return this.serialNumber;
    }
    public String getEmail() {
        return this.email;
    }
    public String getMobileNumber() {
        return this.mobileNumber;
    }
    public void setSerialNumber(Long serialNumber) {
        this.serialNumber = serialNumber;
    }
    public void setName(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public boolean isDeleted() {
        return isDeleted;
    }

    public void setDeleted(boolean deleted) {
        isDeleted = deleted;
    }

    public void setEmail(String email) {
        this.email = email;
    }
    public void setMobileNumber(String mobileNumber) {
        this.mobileNumber = mobileNumber;
    }
}

and it's JPA repository, and I test them in postman :

Database tables :

Postman testing

The whole error :

CodePudding user response：

Have you tried printing the content of @RequestBody Customer customer?

It is because your frontend send first_name while your backend recognizes firstName. You can try changing your JSON from frontend to use camelCase

{
  ...
  firstName: "tets",
  ...
}

Or you can add @JsonProperty annotation in the model

public class Customer {
        ...
        @JsonProperty("firstName")
        @Column(name = "first_name")
        private String firstName;
...
}