GORM .Save 不存储与数据库的“一个对一”关系

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我有结构：

type book struct {
    gorm.model
    title       string      `json:"title"`
    author      string      `json:"author"`
    description string      `json:"description"`
    category    string      `json:"category"`
    publisher   string      `json:"publisher"`
    authorscard authorscard `gorm:"foreignkey:bookid" json:"authorscard"`
}

type authorscard struct {
    //gorm.model   // i purposely don't want to use gorm.model  
    id          uint `gorm:"primarykey"`
    bookid      uint
    name        string `json:"name"`
    age         int    `json:"age"`
    yearofbirth int    `json:"year"`
    biography   string `json:"biography"`
}

我正在尝试制作更新功能：

// controller.go
func updatebook(ctx *gin.context) {
    enablecors(&ctx.writer)
    id := ctx.param("id")
    var updatebook = &models.book{}
    if err := ctx.bindjson(updatebook); err != nil {
        ctx.abortwithstatus(http.statusbadrequest)
        log.fatal(err)
    } else {
        repository.updatebook(updatebook, id)
        ctx.json(http.statusok, updatebook)
        log.println(updatebook)
    }
}

//repository.go
func updatebook(updatebook *models.book, id string) {
    book, db := getbookbyid(id)
    if updatebook.title != "" {
        book.title = updatebook.title
    }

    if updatebook.author != "" {
        book.author = updatebook.author
    }

    if updatebook.publisher != "" {
        book.publisher = updatebook.publisher
    }
    if updatebook.description != "" {
        book.description = updatebook.description
    }
    if updatebook.category != "" {
        book.category = updatebook.category
    }

    if updatebook.authorscard.name != "" {
        book.authorscard.name = updatebook.authorscard.name
    }
    if updatebook.authorscard.age != 0 {
        book.authorscard.age = updatebook.authorscard.age
    }
    if updatebook.authorscard.yearofbirth != 0 {
        book.authorscard.yearofbirth = updatebook.authorscard.yearofbirth
    }
    if updatebook.authorscard.biography != "" {
        book.authorscard.biography = updatebook.authorscard.biography
    }

    db.save(&book)
    // same with db.preload("authorscard").save(&book)
}

问题是：当我发出 put 请求时，我收到完全更新的数据。当我尝试发出 get 请求时，除了相关的 authorscard 之外，我的所有字段都已更新。

put 响应： 200 代码

{
    "id": 0,
    "createdat": "0001-01-01t00:00:00z",
    "updatedat": "0001-01-01t00:00:00z",
    "deletedat": null,
    "title": "test",
    "author": "author",
    "description": "something",
    "category": "category",
    "publisher": "pb",
    "authorscard": {
        "id": 0,
        "bookid": 0,
        "name": "updated",
        "age": 22,
        "year": 1999,
        "biography": "biography updated"
    }
}

之后得到回复：

[
    {
        "ID": 1,
        "CreatedAt": "2022-06-29T14:57:37.489639+03:00",
        "UpdatedAt": "2022-06-29T15:50:11.578724+03:00",
        "DeletedAt": null,
        "title": "Test",
        "author": "author",
        "description": "something",
        "Category": "Category",
        "publisher": "PB",
        "authorscard": {
            "ID": 1,
            "BookID": 1,
            "name": "test",
            "age": 23,
            "year": 1999,
            "biography": "23fdgsdddTEST"
        }
    }
]

如您所见，“authorscard”没有改变。请问有人可以告诉我我做错了什么吗？

正确答案

您需要明确告诉 gorm 存储/更新关联。

db.Session(&gorm.Session{FullSaveAssociations: true}).Updates(&book)

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