i try to use Field-Level Permission in gorm, but it does not work-CodePudding

my data struct is as follows

type DynamicConfig struct {
    gorm.Model
    AppName string `json:"app_name" form:"app_name"`
    Creator string `gorm:"<-:create" json:"creator" form:"creator"`
    Editor string `json:"editor" form:"editor"`
    Metadata string `json:"metadata" form:"metadata"`
}

My idea is that the creator cannot be changed after being created, so i use gorm:"<-:create", docs says it can allow read and create. There is such a piece of data in the database.

{
      "ID": 4,
      "CreatedAt": "2021-11-30T13:05:31Z",
      "UpdatedAt": "2021-12-01T06:22:02Z",
      "DeletedAt": null,
      "app_name": "test3",
      "creator": "xx",
      "editor": "yy",
      "metadata": "test3"
}

Here is my update method:

func UpdateDynamicConfig(dc DynamicConfig) error {
    res, err := GetDynamicConfig(DynamicConfig{
        AppName:  dc.AppName,
    })
    if err != nil {
        return err
    }else if len(res) == 0 {
        return errors.New("app conf not exists")
    }else if len(res) != 1 {
        return errors.New("more than one config meet the criteria, please check")
    }

    config := res[0]
    
    result := DB.Model(&config).Updates(dc)
    return result.Error
}

I call the method like this

    config := model.DynamicConfig{AppName: "test3", Creator: "xxxx"}
    model.UpdateDynamicConfig(config)

then the creator is update to xxxx. How can i prevent a field from being updated？ Please help me, thank you very much！

CodePudding user response：

Please use Omit it will not consider the column while updating the data in table. Please refer this link for Omit

result := DB.Model(&config).Omit("creator").Updates(dc)

For field level permission please refer this link.

You can try with this

Name string `gorm:"->;<-:create"` // allow read and create

CodePudding user response：

The easiest way to omit a field in the update is to use the Omit function:

result := DB.Model(&config).Omit("Creator").Updates(dc)