Question

作为this的后续问题，我想要一个User域类，该域与BasicProfile域类User具有可选的一对一关系{{1}作为拥有者，可能有也可能没有个人资料。我有这个部分想通了。我还想要的是AcademicProfile域类与作为所有者的User AcademicProfile之间的可选一对一关系，以便AcademicProfile可以或可以没有User。当我尝试按照我第一次一对一关系的方式复制时，它不起作用。这是我的课程。

class User {

    String username
    String password
    String email
    AcademicProfile academicProfile
    Date dateCreated
    Date lastUpdated

    static hasOne = [basicProfile: BasicProfile]

    static constraints = {
        username size: 3..20, unique: true, nullable: false, validator: { _username ->
            _username.toLowerCase() == _username
        }
        password size: 6..100, nullable: false, validator: { _password, user ->
            _password != user.username
        }
        email email: true, blank: false
        basicProfile nullable: true
    }
}

class BasicProfile extends Profile {

    User user
    Date dateCreated
    Date lastUpdated

}

class AcademicProfile extends Profile {

    String dblpId
    String scholarId
    String website
    Date dateCreated
    Date lastUpdated

    static hasOne = [user: User]
    static hasMany = [publications: Publication]

    static constraints = {
        dblpId nullable: true
        scholarId nullable: true
        website nullable: true, url: true
        publications nullable: true
        user nullable: true
    }
}

class Profile {
    String firstName
    String middleName
    String lastName
    byte[] photo
    String bio

    static constraints = {
        firstName blank: false
        middleName nullable: true
        lastName blank: false
        photo nullable: true, maxSize: 2 * 1024**2
        bio nullable: true, maxSize: 500
    }

    static mapping = {
        tablePerSubclass true
    }
}

当我运行它时，我收到错误：Field error in object 'org.academic.User' on field 'academicProfile': rejected value [null];。我不明白我做错了什么。

Answer 1

您必须在User类中为nullable:true添加AcademicProfile academicProfile约束，因为您提到您需要在AcademicProfile＆amp ;;之间建立'可选'关系。用户。

错误本身是不言自明的，你不能创建一个User类的实例，而不为academicProfile属性提供非null值。

如何在三个域类之间建立多个一对一关系

1 个答案: