如何用GORM获取相关数据？

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问题内容

我想从其他表获取相关数据

我有以下模型结构

type community struct {
    id       string            `json:"id" gorm:"primarykey"`
    name     string            `json:"name"`
    category communitycategory `json:"category" gorm:"foreignkey:id"`
}
type communitycategory struct {
    id   uint32 `json:"id" gorm:"primarykey"`
    name string `json:"name"`
}

我获取数据的代码是这样的

community := community{id: 1}
database.debug().joins("communitycategory").first(&community)

有了这些，我收到以下错误 error：对表“communities”(sqlstate 42p01) 的 from 子句条目的引用无效

查看gorm的调试日志，查询是这样的

SELECT "communities"."id","communities"."name","communities"."introduction","communities"."address","communities"."postal_code","communities"."country","communities"."address1","communities"."address2","communities"."prefecture","communities"."city","communities"."lat","communities"."lng","communities"."phone","communities"."email","communities"."external_link_1","communities"."external_link_2","communities"."image_url","communities"."access","communities"."description","communities"."contact_name","communities"."contact_phone","communities"."contact_email","communities"."is_enabled","communities"."created_at","communities"."updated_at" FROM "communities" CommunityCategory WHERE "communities"."id" = '25b1eadf-1004-40b7-b9a2-325a83bcb938' ORDER BY "communities"."id" LIMIT 1

我做错了吗？哈哈

解决方案

通过按如下方式定义我的结构来修复此问题。我在 community 结构中添加了一个新字段 categoryid 并将外键更改为这个新字段

type community struct {
    id         string            `json:"id" gorm:"primarykey"`
    name       string            `json:"name"`
    categoryid uint32
    category   communitycategory `json:"category" gorm:"foreignkey:categoryid"`
}

type communitycategory struct {
    id   uint32 `json:"id" gorm:"primarykey"`
    name string `json:"name"`
}

然后在查询时，您可以像这样执行连接：

community := Community{ID: 1}
database.Model(&Community{}).Joins("Category").First(&community)

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