hibernate - Grails - .save() 上的多对一关系 null id

Question

我正在尝试在我的数据库中插入两个条目（一个用户和一个照片），其中照片属于用户，但是当我将用户保存到数据库时出现错误

列“user_id”不能为空

照片.groovy：

class Photo {

    Boolean active = 1
    Boolean approved = 0
    Date dateAdded = new Date()
    String filterName
    String senderIp
    String originalUrl
    String editedUrl
    User user

    static belongsTo = [User]
    static mapping = {
        active defaultValue: 1
        approved defaultValue: 0
        user column: 'user_id'
    }
    static constraints = {
        originalUrl maxSize: 512
        editedUrl maxSize: 512
        senderIp maxSize: 15
    }
}

用户.groovy

class User {

    String address
    String number
    Date birthday
    String city
    String complement
    String cpf
    String guardianCpf
    String guardianName
    String email
    String firstName
    String lastName
    String mobile
    String neighborhood
    String phone
    String rg
    String sex
    String state
    String zipcode

    static hasMany = [photos: Photo]

    static constraints = {
        address maxSize: 256
        complement maxSize: 32
        city maxSize: 64
        complement nullable: true, maxSize: 32
        cpf maxSize: 11, unique: true
        guardianCpf maxSize: 11, nullable: true
        guardianName maxSize: 256, nullable: true
        email email: true, blank: false
        firstName maxSize: 128
        lastName maxSize: 128
        mobile maxSize: 12
        neighborhood maxSize: 128
        phone maxSize: 12
        rg maxSize: 9, unique: true
        sex maxSize: 1
        state maxSize: 2
        zipcode maxSize: 9
    }
}

用户服务.groovy

@Transactional
class UserService {
    def grailsApplication
    def registerUser(String address, String number, Date birthday, String city, String complement,
            String cpf, String guardianCpf, String email, String firstName,
            String lastName, String mobile, String neighborhood, String phone,
            String rg, String sex, String state, String zipcode, String filterName, String originalUrl, String editedUrl, String senderIp) {
        def status = 0
        def content = ""
        def u = new User(
                address         : address,
                number          : number,
                birthday        : birthday,
                city            : city,
                complement      : complement,
                cpf             : cpf,
                email           : email,
                firstName       : firstName,
                lastName        : lastName,
                mobile          : mobile,
                neighborhood    : neighborhood,
                phone           : phone,
                rg              : rg,
                sex             : sex,
                state           : state,
                zipcode         : zipcode,
                guardianCpf     : guardianCpf)
        //I EDITED THIS PART OF THE CODE, TO SOLVE THE CODE SEE BELOW
        if (u.validate()){
            def p = new Photo(
                    filterName : filterName,
                    originalUrl : originalUrl,
                    editedUrl : editedUrl,
                    senderIp : senderIp,
                    user : u
                    )
            if (p.validate()){
                try{

                    u.addToPhotos(p).save(failOnError:true)
                    status = 1
                    content = "SUCCESS"
                }
                catch(e){
                    status = 0
                    content = grailsApplication.config.serviceErrors.databaseError
                }
            }
            else{
                status = 0
                content = grailsApplication.config.serviceErrors.invalidUserData + ": n"
                p.errors.allErrors.each {
                    content += it.toString() + "'"
                }
            }
        }
        else {
            status = 0
            content = grailsApplication.config.serviceErrors.invalidUserData + ": n"
            u.errors.allErrors.each {
                content += it.toString() + "'"
            }
        }
        return [status: status, content: content]
    }
}

有人能帮我吗？

编辑：现在我在添加照片之前保存用户，现在我收到错误：

seviranaembalagem.User 条目中的空 id（发生异常后不要刷新会话）

try{
    u.save(failOnError:true)
    u.addToPhotos(p)
    p.save(flush: true)
    status = 1
    content = "SUCCESS"
}
catch(e){
    status = 0
    content = grailsApplication.config.serviceErrors.databaseError
}

EDIT2：在 UserService.groovy 使用此代码解决了问题：

if (u.validate()){
    u.save()
    def p = new Photo(
            filterName : filterName,
            originalUrl : originalUrl,
            editedUrl : editedUrl,
            senderIp : senderIp,
            user : u
            )
    if (p.validate()){
        try{                    
            p.save(flush:true)
            status = 1
            content = "SUCCESS"
        }
        catch(e){
            status = 0
            content = grailsApplication.config.serviceErrors.databaseError + e
        }
    }
    else{
        status = 0
        content = grailsApplication.config.serviceErrors.invalidUserData + ": n"
        p.errors.allErrors.each {
            content += it.toString() + "'"
        }
    }
}