如何通过基于两个属性检索特定 object 的方法名称来实现此 Spring 数据 JPA 查询？

Question

I am working on a Spring Boot project using Spring Data JPA trying to adopt the "query by method name" style in order to define my queries into repositories.

I am finding some difficulties trying to implement a select query retrieving the list of objects based on two different "where condition". I will try to explain what I have to do.

First of all this is my main entity class named Wallet :

@Entity
@Table(name = "wallet")
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class Wallet implements Serializable {

    private static final long serialVersionUID = 6956974379644960088L;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;


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

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

    @ManyToOne
    @EqualsAndHashCode.Exclude          // Needed by Lombock in "Many To One" relathionship to avoid error
    @JoinColumn(name = "fk_user_id", referencedColumnName = "id")
    @JsonBackReference(value = "user-wallets")
    private User user;

    @ManyToOne
    @EqualsAndHashCode.Exclude          // Needed by Lombock in "Many To One" relathionship to avoid error
    @JoinColumn(name = "fk_coin_id", referencedColumnName = "id")
    private Coin coin;


    @ManyToOne
    @JoinColumn(name = "type", referencedColumnName = "id")
    private WalletType walletType;


    public Wallet(String address, String notes, User user, Coin coin, WalletType walletType) {
        super();
        this.address = address;
        this.notes = notes;
        this.user = user;
        this.coin = coin;
        this.walletType = walletType;
    }
    
    
}

As you can see a wallet is directly binded to a specific User object and to a specific Coin object.

For completeness this is the code of my User entity class:

@Entity
@Table(name = "portal_user")
@Getter
@Setter
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class User implements Serializable {
     
    private static final long serialVersionUID = 5062673109048808267L;
    
    @Id
    @Column(name = "id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;
    
    @Column(name = "first_name")
    @NotNull(message = "{NotNull.User.firstName.Validation}")
    private String firstName;
    
    @Column(name = "middle_name")
    private String middleName;
    
    @Column(name = "surname")
    @NotNull(message = "{NotNull.User.surname.Validation}")
    private String surname;
    
    @Column(name = "sex")
    @NotNull(message = "{NotNull.User.sex.Validation}")
    private char sex;
    
    @Column(name = "birthdate")
    @NotNull(message = "{NotNull.User.birthdate.Validation}")
    private Date birthdate;
    
    @Column(name = "tax_code")
    @NotNull(message = "{NotNull.User.taxCode.Validation}")
    private String taxCode;
    
    @Column(name = "e_mail")
    @NotNull(message = "{NotNull.User.email.Validation}")
    private String email;
    
    @Column(name = "pswd")
    @NotNull(message = "{NotNull.User.pswd.Validation}")
    private String pswd;
    
    @Column(name = "contact_number")
    @NotNull(message = "{NotNull.User.contactNumber.Validation}")
    private String contactNumber;
    
    @Temporal(TemporalType.DATE)
    @Column(name = "created_at")
    private Date createdAt;
    
    @Column(name = "is_active")
    private boolean is_active;
    
    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "user", orphanRemoval = true)
    @JsonManagedReference(value = "address")
    private Set<Address> addressesList = new HashSet<>();
    
    @ManyToMany(cascade = { CascadeType.MERGE })
    @JoinTable(
        name = "portal_user_user_type", 
        joinColumns = { @JoinColumn(name = "portal_user_id_fk") }, 
        inverseJoinColumns = { @JoinColumn(name = "user_type_id_fk") }
    )
    private Set<UserType> userTypes;


    @ManyToOne(fetch = FetchType.LAZY)
    @JsonProperty("subagent")
    private User parent;

    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "user", orphanRemoval = true)
    @JsonManagedReference(value = "user-wallets")
    private Set<Wallet> wallets = new HashSet<>();


    public User() {
        super();
        // TODO Auto-generated constructor stub
    }


    public User(String firstName, String middleName, String surname, char sex, Date birthdate, String taxCode,
            String email, String pswd, String contactNumber, Date createdAt, boolean is_active) {
        super();
        this.firstName = firstName;
        this.middleName = middleName;
        this.surname = surname;
        this.sex = sex;
        this.birthdate = birthdate;
        this.taxCode = taxCode;
        this.email = email;
        this.pswd = pswd;
        this.contactNumber = contactNumber;
        this.createdAt = createdAt;
        this.is_active = is_active;
    }
    

}

and this is the code of my Coin entity class:

@Entity
@Table(name = "coin")
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class Coin implements Serializable {

    private static final long serialVersionUID = 6956974379644960088L;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    @Column(name = "name")
    @NotNull(message = "{NotNull.Coin.name.Validation}")
    private String name;

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

    @Column(name = "code", unique = true)
    @NotNull(message = "{NotNull.Coin.code.Validation}")
    private String code;

    @Type(type="org.hibernate.type.BinaryType")
    @Column(name = "logo")
    private byte[] logo;


}

Then I have this WalletRepository interface:

public interface WalletRepository extends JpaRepository<Wallet, Integer> {

}

Here I need to define a query by name method that retrieve a specific wallet of a specific User (I think that I can query by the id field of the User ) and based and related to a specific Coin (I think that I can query by the id fied of the Coin ).

How can I implement a behavior like this?

Answer 1

The following should work:

public interface WalletRepository extends JpaRepository<Wallet, Integer> {
    List<Wallet> findByUserIdAndCoinId();
}

You can read more about this at:

• https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#jpa.query-methods.query-creation
• https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#repository-query-keywords