Question

我有两个域类：

class Person {

    String lastname
    String firstname
    String alias
    Date birthday
    String notes
    static belongsTo = [addressBook: AddressBook, mainAddress: Address]
    static hasMany = [tags: Tag, addresses: Address]

    static constraints = {
        mainAddress nullable: true
        addresses nullable: true
        alias nullable: true
        birthday: nullable: true
        tags nullable: true
        notes nullable: true
    }
}

和

class Address {

    AddressType addressType

    static belongsTo = [person: Person]
    String company
    String street
    String zipCode
    String city
    String eMail
    String phone
    String mobile
    String website

    static constraints = {
        person nullable: true
        company nullable: true
        website nullable: true
    }
}

每个人都有多个地址，可以将一个地址定义为主地址。

在我的控制器里面我做了一个

params.max = Math.min(max ?: 10, 100)
respond Person.list(params)

加载所有地址的所有人。我收到的person-objects包含一个包含所有地址和mainAddress的地址列表。但是，用作主地址的地址在两个对象（列表中的一个和mainAddress对象）中只有空（空）字段。当我没有设置mainAddress时，address-list中的address-object会自动设置所有字段。数据库字段（我到目前为止使用in-memory-db）似乎是正确的：

create table address (id bigint generated by default as identity, version bigint not null, address_type varchar(255) not null, city varchar(255) not null, company varchar(255), e_mail varchar(255) not null, mobile varchar(255) not null, person_id bigint, phone varchar(255) not null, street varchar(255) not null, website varchar(255), zip_code varchar(255) not null, primary key (id))
create table person (id bigint generated by default as identity, version bigint not null, address_book_id bigint not null, alias varchar(255), birthday timestamp not null, firstname varchar(255) not null, lastname varchar(255) not null, main_address_id bigint, notes varchar(255), primary key (id))

有没有人知道，为什么我的地图不起作用？

感谢您的提前帮助

罗兰

Answer 1

您的模型存在许多问题，最严重的是person-mainAddress关系没有所有者，即每一方belongsTo另一方。如果可能的话，我会将你的模型简化为

class Person {
    // non-address properties omitted, because they're not relevant to this question
    static hasMany = [addresses: Address]

    Address getMainAddress() {
        Address.createCriteria().get {
            eq 'person', this
            eq 'isMain', true   
        }
    }

    static transients = ['mainAddress']

    static constraints = {

        addresses nullable: true, validator: { addresses ->

            // this prevents a person from having more than one main address
            addresses?.count { it.isMain } <= 1
        }
    }
}

class Address {
    // non-person properties omitted, because they're not relevant to this question     
    boolean isMain = false

    static belongsTo = [person: Person]

    static constraints = {
        // is it really OK for an address not to be associated with a person?
        person nullable: true
    }
}

我认为这符合您的要求，但是更简单的模型，因为Person和Address

之间只有一个（一对多）关系

Answer 2

我现在找到了解决方案：

class Person {

    Address mainAddress
    static hasMany = [addresses: Address]

    static constraints = {
        addresses nullable: true
        mainAddress nullable: true, unique: true
    }

    static mapping = {
        addresses joinTable: [name: 'person_address',key: 'person_id', column: 'address_id']
        mainAddress lazy: false
    }
}

class Address {
}

这样，地址映射到连接表person_address，而mainAddress通过地址表中的main_address_id映射。需要“mainAddress：lazy”映射，因为否则不会填充mainAddress的字段。

grails gorm null字段

2 个答案: