Spring Boot 中的处理程序方法正在保存新记录，而不是更新数据库中已存在的记录以进行 put 请求

Question

I am trying to update an existing record in my database for a put request in spring boot.

Incoming Request -

Handler method in controller class

  // put method for updating record
    @PutMapping("/accounts/{id}")
    public Account putAccount(@RequestBody Account account, @PathVariable("id") int id) {
        System.out.println(account);
        Account ac = this.accountServices.addAccount(account);
        // save method of crud repository also updates if data is already present
        return ac;
    }

AccountServices class addAccount() method

// add an account
    public Account addAccount(Account account) {
        Account acc = this.accountRepository.save(account);
        return acc;
    }

AccountRepository interface

public interface AccountRepository extends CrudRepository<Account, Integer> {
//custom finder method to get book record with id
}

For every request it is adding new record instead of updating already existing record. Someone please help here.

Adding Account class

@Entity
@Table(name = "Account")
public class Account {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public int accountNumber;
    public String accountType;
    public int balance;

    @ManyToMany(cascade = CascadeType.ALL)
    @JsonManagedReference
    @JsonIgnore 
    private List<Customer> customers;
//skipped constructors, getters and setters
}

Answer 1

似乎您的模型的 ORM 映射会为每个save操作生成模型对象的 ID（例如@Generated Value(strategy = GenerationType.IDENTITY) ），并且在这种情况下save()不会更新记录。

Answer 2

You need to make sure your Account object have ID in it before you save, If ID is null for the object you're going to save, It'll be saved as new entry.

In your controller you can do this -

@PutMapping("/accounts/{id}")
public Account putAccount(@RequestBody Account account, @PathVariable("id") int id) {
    System.out.println(account);
    account.setId(id);
    Account ac = this.accountServices.addAccount(account);
    // save method of crud repository also updates if data is already present
    return ac;
}

Answer 3

Maybe you can try something like that

private void _setPackAddress(Pack objectPack, Pack pacDao) {
        if (objectPack.getPackageAddress() != null) {
            pacDao.getPackageAddress().setCity(objectPack.getPackageAddress().getCity());
            pacDao.getPackageAddress().setNumber(objectPack.getPackageAddress().getNumber());
            pacDao.getPackageAddress().setPostalCode(objectPack.getPackageAddress().getPostalCode());
            pacDao.getPackageAddress().setStreet(objectPack.getPackageAddress().getStreet());
            
        }
}

And where can you see from where parameters come

        Pack pacDao = this.packRepository.findById(id).orElseThrow(() -> new OpenApiResourceNotFoundException("Pack not found:: " + id));

not directly like that

private void _setPackAddress(Pack objectPack, Pack pacDao) {
 if (objectPack.getPackageAddress() != null) {
    pacDao.setPackageAddress(objectPack.getPackageAddress());
 }
}

I also encountered this problem, but I solved it that way. I hope this post to be helpful for you. Keep coding :-)