duanbenzan4050 2016-07-08 15:16
浏览 354
已采纳

Golang Gorm:是否可以通过many2many关系删除记录?

I have a many2many structure similar to GORM's example:

// User has and belongs to many languages, use `user_languages` as join table
type User struct {
    gorm.Model
    Languages         []Language `gorm:"many2many:user_languages;"`
}

type Language struct {
    gorm.Model
    Name string
}

db.Model(&user).Related(&languages)

Let's say I create a user and it has two associated languages.

I fetch a user record from the database and remove one language from the user's Languages array. I then save the user with gorm:save_associations set to true.

I would expect GORM to delete the record associating the user to this language (in the association table that GORM manages). However, it is not deleted. Is this expected?

Is it possible to delete many2many association records by removing a language from the Languages list on the user record and then saving the user? If not, how should this be done in GORM?

Update

I found a solution to this question, but not sure it's the best way to do this. I store the current languages, clear all the associations, then add back the languages, then save.

languages := user.Languages
DB.Model(&user).Association("Languages").Clear()
user.Languages = languages
  • 写回答

3条回答 默认 最新

  • douying9296 2016-07-08 21:15
    关注

    I found a solution to this question, but not sure it's the best way to do this. I store the current languages, clear all the associations, then add back the languages, then save.

    languages := user.Languages 
    DB.Model(&user).Association("Languages").Clear()
    user.Languages = languages
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(2条)

报告相同问题?

悬赏问题

  • ¥15 PADS Logic 原理图
  • ¥15 PADS Logic 图标
  • ¥15 电脑和power bi环境都是英文如何将日期层次结构转换成英文
  • ¥20 气象站点数据求取中~
  • ¥15 如何获取APP内弹出的网址链接
  • ¥15 wifi 图标不见了 不知道怎么办 上不了网 变成小地球了
  • ¥50 STM32单片机传感器读取错误
  • ¥15 (关键词-阻抗匹配,HFSS,RFID标签天线)
  • ¥15 机器人轨迹规划相关问题
  • ¥15 word样式右侧翻页键消失