gorm 中不受支持的关系

Question

我正在尝试从一对多关系中预加载数据，但我总是收到“ApiKeys：模式客户端不支持的关系”错误。（结构是指针的原因是因为我使用的是 gqlgen，这是默认配置）

type Client struct {
    //  Client ID
    ID int `json:"id"`
    UserName string `json:"userName"`
    //  Client login hashed password
    Password string `json:"password"`
    //  ApiKeys
    APIKeys []*APIKey `json:"apiKeys"`
}

type APIKey struct {
    //  ApiKey Index
    ID int `json:"id"`
    //  ApiKey Value
    Key string `json:"key"`
    //  ApiKey Client Relation
    ClientID int `json:"clientID"`
    //  ApiKey Client Info
    Client *Client `json:"client"`
}

这是调用ApiKeys Preload的函数

func (r *queryResolver) ClientInfoResolver(username string, password string) (*model.Client, error) {
    var clients []*model.Client
    var client *model.Client
    query := r.Resolver.DB

    query = query.Where("user_name = ? AND password = ?", username, password).Preload("ApiKeys").Find(&clients)

    if query.Error != nil {
        return client, query.Error
    }
    return clients[0], nil
}

根据 gorm 的文档，我了解到该关系的外键是 ClientID，尽管它不是显式的（通过指定它也不起作用）我理解错了吗？

Answer 1

您将 APIKeys 列为结构字段名称，但尝试使用 ApiKeys 作为 FK。

.Preload("ApiKeys")
// Should be
.Preload("APIKeys")

或者，如果您想使用 ApiKeys 作为外键，use a Gorm struct tag to do this.

完整的工作示例

package main

import (
    "fmt"
    "gorm.io/driver/sqlite"
    "gorm.io/gorm"
)

type Client struct {
    //  ApiKey Index
    ID int `json:"id"`
    UserName string `json:"userName"`
    //  Client login hashed password
    Password string `json:"password"`
    //  ApiKeys
    APIKeys []*APIKey `json:"apiKeys"`
}

type APIKey struct {
    //  ApiKey Index
    ID int `json:"id"`
    //  ApiKey Value
    Key string `json:"key"`
    //  ApiKey Client Relation
    ClientID int `json:"clientID"`
    //  ApiKey Client Info
    Client *Client `json:"client"`
}

func main() {

    db, err := gorm.Open(sqlite.Open("many2many.db"), &gorm.Config{})
    if err != nil {
        panic("failed to connect database")
    }

    // Migrate the schema
    err = db.AutoMigrate(&APIKey{}, &Client{})
    if err != nil {
        fmt.Print(err)
    }

    clientOne := Client{
        UserName:          "Client One",
    }
    db.Create(&clientOne)

    apiKeyOne := APIKey{
        Key:"one",
        Client: &clientOne,
    }
    apiKeyTwo := APIKey{
        Key:"two",
        Client: &clientOne,
    }

    db.Create(&apiKeyOne)
    db.Create(&apiKeyTwo)

    // Fetch from DB
    fetchedClient := Client{}

    db.Debug().Preload("APIKeys").Find(&fetchedClient, clientOne.ID)
    fmt.Println(fetchedClient)

    db.Delete(&clientOne)
    db.Delete(&apiKeyOne)
    db.Delete(&apiKeyTwo)
}

Answer 2

解决了吗？我也遇到了同样的问题。
当我尝试从一对多关系中预加载数据时，
report:unsupported 架构 TeacherInfo 的关系

github.com/99designs/gqlgen v0.13.0

gorm.io/gorm v1.21.8

models_gen:

func (TeacherInfo) TableName() string {
return "teacher_info"

}

type TeacherInfo struct {
ID           int             `json:"id" gorm:"primaryKey"`
Name         string          `json:"name"`
Avatar       string          `json:"avatar" `
Info         string          `json:"info" `
Score        float64         `json:"score" `
Role         int             `json:"role" `
TeacherScore []*TeacherScore `json:"teacherScore" gorm:"foreignkey:TID; references:ID"`

}

func (TeacherScore) TableName() string {
return "teacher_score"

}

type TeacherScore struct {
ID      int     `json:"id" `
TID     int     `json:"t_id" `
Comment string  `json:"comment" `
UID     int     `json:"u_id" `
Score   float64 `json:"score" `

}

解析器：

func (r *queryResolver) TeacherScore(ctx context.Context, id int) (*model.TeacherInfo, error) {
var teacherInfo model.TeacherInfo


wrong: dao.DB.Debug().Preload("teacher_score").First(&teacherInfo)

right:  here is teacherInfo's cloume TeacherScore
dao.DB.Debug().Preload("TeacherScore").First(&teacherInfo)

    return &teacherInfo, nil

}

已解决

gorm 中不受支持的关系

Unsupported relations in gorm

postgresql

go

go-gorm

gqlgen

完整的工作示例