一對多關系，springboot中如何保存或更新資料

我正在為我工??作的公司構建 API，這是我第一次使用 Spring Boot，所以我遇到了一些問題。

我有 2 個班級，Compania（家長）和 Office（兒童）。Compania 類與 Office 具有 OneToMany 關系，Office 具有 ManyToOne，我正在努力尋找如何添加一些子項或編輯其中一個子項。現在我的課程如下：

公司（母公司）

@Entity(name = "Compania")
@Table(
    name = "compania"
)
public class Compania {
    @Id
    @SequenceGenerator(
        name = "compania_sequence",
        sequenceName = "compania_sequence",
        allocationSize = 1
    )
    @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "compania_sequence"
    )
    @Column(
        nullable = false
    )
    private Long id;


    @Column(
        name = "name",
        nullable = false,
        unique = true
    )
    private String name;

    @Column(
        name = "dominio",
        nullable = true
    )
    private String dominio;

    @Column(
        name = "altas"
    )
    private String altas;

    @Column(
        name = "bajas"
    )
    private String bajas;

    @OneToMany(
        mappedBy = "compania",
        cascade = CascadeType.ALL,
        fetch = FetchType.LAZY,
        orphanRemoval = true
    )
    private List<Office> office;

...Constructors...
... Getters and Setters...

辦公室（兒童）

@Entity()
@Table()
public class Office {
    @Id
    @SequenceGenerator(
        name = "office_sequence",
        sequenceName = "office_sequence",
        allocationSize = 1
    )
    @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "office_sequence"
    )
    @Column(
        nullable = false
    )
    @JsonIgnore
    private Long id;

    @Column(
        name = "idRef",
        nullable = false
    )
    private int idRef;

    @Column(
        name = "title",
        nullable = false
    )
    private String title;

    @Column(
        name = "name"
    )
    private String name;
    @Column(
        name = "path"
    )
    private String path;

    @ManyToOne(
        fetch = FetchType.LAZY
    )
    @JoinColumn(
        name = "compania_id",
        referencedColumnName = "id"
    )
    private Compania compania;

    ...Constructors...
    ... Getters and Setters...

我想在我的父物件（具有 OneToMany 關系的物件）中保存或編輯資料為了實作這一點，我想到了 2 種方法，但我對這兩種方法都有問題。

第一個將保存 Compania (Parent) 類中的所有內容。像這樣，我將 Compania 類的 id 和 JSON 物件作為 Office 物件傳遞：

public void addOfficeTest(Long companiaId, Office office) {
        // OPTION 1 - Add directly the office to the office list of the Compania Object (parent), then save it using Compania repository
        if (office.getId() != null) {
            office.setId(null);
        }
        Compania companiaFound = companiaRepository.findById(companiaId).get();
        List<Office> listaOffice = companiaFound.getOffice();
        listaOffice.add(office);
        companiaFound.setOffice(listaOffice);
        // method to set references id for user use...
        setIdReferencia(companiaEnc, true, false);
        companiaRepository.save(companiaEnc);

With this method, my problem is that is like I'm not being able to save my entities, when I make a GET to obtain my Companias I get the Office as an empty string. like this:

{
        "id": 1,
        "name": "Test Compania",
        "dominio": "domain",
        "altas": "OU=nn",
        "bajas": "none",
        "office": []
}

The other method I thought was this one, saving the Office with the Office repository, but that returned an infinite recursion error when I tried to fetch my Compania (as I'm saving the compania in office)...

public void addOfficeTest(Long companiaId, Office office) {
        // OPTION 2 - Save Office with the repository office
        if (office.getId() != null) {
            office.setId(null);
        }
        Compania companiaEnc = companiaRepository.findById(companiaId).get();
        office.setCompania(companiaEnc); // This causes recursion
        officeRepository.save(office); 

So I'm stuck here because I don't know how to do a PUT or a POST for my child objects. I don't know if something is wrong with my code or what. Maybe it has an easy solution, but I really can't find it. If someone could help giving me an example of how to do a POST and a PUT I would be very grateful...

Thanks

uj5u.com熱心網友回復：

鑒于您有雙向關系，我認為您缺少Compania在新的Office. 沿著以下幾行的內容：

public void addOfficeTest(Long companiaId, Office office) {
    // OPTION 1 - Add directly the office to the office list of the Compania Object (parent), then save it using Compania repository
    if (office.getId() != null) {
        office.setId(null);
    }
    Compania companiaFound = companiaRepository.findById(companiaId).get();
    office.setCompania(companiaFound); // The new line
    List<Office> listaOffice = companiaFound.getOffice();
    listaOffice.add(office);
    companiaFound.setOffice(listaOffice); // You actually don't need this because you've changed the List already
    // method to set references id for user use...
    setIdReferencia(companiaEnc, true, false);
    companiaRepository.save(companiaEnc);
}

標籤：java json spring-boot hibernate jpa

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