我不知道如何檢查我的數據庫中是否User有某個Role。具體來說，我想運行一個計數查詢 - 并希望避免在數據庫之外進行處理。我們的代碼庫使用org.springframework.data.repository.CrudRepository- 因此我們@Query用來指定復雜的查詢。( org.springframework.data.jpa.repository.Query)此 SQL 查詢返回我想要的內容：SELECT Count(*) FROM user where id in (    select user_id     from user_role     where role_type = 'ROLE_USER');但我無法得到我@Query想要的回報。這是一些代碼：User 班級：@Entity@ApiModel(description = "Represents an user of the system")public class User implements Serializable {    private static final long serialVersionUID = 1L;    @Id    @GeneratedValue(strategy=GenerationType.IDENTITY)    @Column(name = "ID")    @ApiModelProperty(value = "The ID of the user", required = true)    private Long id;    @Column(name = "USERNAME", unique = true)    @ApiModelProperty(value = "The userName of the user", required = true)    private String username;    @Column(name = "STATUS", nullable=false)    @Enumerated(EnumType.STRING)    @ApiModelProperty(value = "The status of the user", required = true)    private UserStatus status;    @Column(name = "PASSWORD")    @ApiModelProperty(value = "The encrypted password of the user")    private String password;    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true)    @JoinColumn(name = "USER_ID", nullable=false)    @ApiModelProperty(value = "The role of the user", required = true)    private Set<UserRole> userRoles;}UserRole 班級：@Entitypublic class UserRole implements Serializable {    @Id    @Column(name = "ID")    @GeneratedValue(strategy = GenerationType.AUTO)    private Long id;    @Column(name = "ROLE_TYPE")    @Enumerated(EnumType.STRING)    private UserRoleType roleType;    @ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)    @JoinColumn(name = "USER_ID", nullable=false, insertable=false, updatable=false)    @ApiModelProperty(value = "The id the user (link to User table)", required = true)    private User user;}數據庫非常簡單，包含User表和User_Role表。該User表有Id, Username, Password,Status列。