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Gorm 如何支持枚举值

来源：stackoverflow 2024-02-16 15:39:23 0浏览收藏

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问题内容

大家好，我是 go 和 gorm 的新手，我正在使用 postgres 构建一个简单的 web 服务，我在让我的模型支持枚举值时遇到了问题，经过一些研究，我找到了一种方法来做到这一点。但我开始遇到新的错误，在在线研究资源后我似乎无法修复这些错误。

每当我尝试从数据库中获取用户时，我都会收到此错误：

panic: interface conversion: interface {} is string, not []uint8
 
 -> userservice/models.(*roleallowed).scan
 ->   /users/cipher/work/frontendlabs/shopvending/userservice/models/user.model.go:22

    database/sql.convertassignrows
      /usr/local/go/src/database/sql/convert.go:385
    database/sql.convertassignrows
      /usr/local/go/src/database/sql/convert.go:428
    database/sql.(*rows).scan
      /usr/local/go/src/database/sql/sql.go:3287
    gorm.io/gorm.(*db).scanintostruct
      /users/cipher/go/pkg/mod/gorm.io/[email protected]/scan.go:67
    gorm.io/gorm.scan
      /users/cipher/go/pkg/mod/gorm.io/[email protected]/scan.go:293
    gorm.io/gorm/callbacks.query
      /users/cipher/go/pkg/mod/gorm.io/[email protected]/callbacks/query.go:26
    gorm.io/gorm.(*processor).execute
      /users/cipher/go/pkg/mod/gorm.io/[email protected]/callbacks.go:130
    gorm.io/gorm.(*db).first
      /users/cipher/go/pkg/mod/gorm.io/[email protected]/finisher_api.go:129
    userservice/services.userservice.finduserbyemail
      /users/cipher/work/frontendlabs/shopvending/userservice/services/user.service.go:25
    userservice/handlers.manuallogin
      /users/cipher/work/frontendlabs/shopvending/userservice/handlers/auth.handler.go:24
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5.(*mux).routehttp
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/mux.go:442
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5.(*mux).servehttp
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/mux.go:71
    github.com/go-chi/chi/v5.(*mux).mount.func1
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/mux.go:314
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5.(*mux).routehttp
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/mux.go:442
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5/middleware.timeout.func1.1
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/middleware/timeout.go:45
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    userservice/middlewares.commonmiddleware.func1
      /users/cipher/work/frontendlabs/shopvending/userservice/middlewares/contenttype.go:8
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5/middleware.recoverer.func1
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/middleware/recoverer.go:38
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5/middleware.requestlogger.func1.1
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/middleware/logger.go:57
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5/middleware.realip.func1
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/middleware/realip.go:35
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5/middleware.requestid.func1
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/middleware/request_id.go:76
    net/http.handlerfunc.servehttp
      /usr/local/go/src/net/http/server.go:2109
    github.com/go-chi/chi/v5.(*mux).servehttp
      /users/cipher/go/pkg/mod/github.com/go-chi/chi/[email protected]/mux.go:88
    net/http.serverhandler.servehttp
      /usr/local/go/src/net/http/server.go:2947
    net/http.(*conn).serve
      /usr/local/go/src/net/http/server.go:1991
    created by net/http.(*server).serve
      /usr/local/go/src/net/http/server.go:3102

我尝试将字节转换为字符串，但仍然收到错误。

我的用户服务文件：

package services

import (
    "github.com/sirupsen/logrus"
    "userservice/database"
    "userservice/dto"
    "userservice/models"
)

type userservice struct{}

//func (u userservice) finduserbyid(id int) *models.user {
//  user := u.user
//  if err := database.instance.where("id = ?", id).first(&user); err != nil {
//      logrus.errorf("can not find user with id %d", id)
//      return nil
//
//  }
//  return user
//
//}

func (u userservice) finduserbyemail(email string) *models.user {
    var user models.user
    if err := database.instance.where("email = ?", email).first(&user); err.error != nil {
        logrus.errorf("can not find user with email %s", err.error)
        return nil

    }
    return &user

}

func (u userservice) createuser(newuser dto.createnewuserdto) *models.user {
    createnewuser := models.user{
        email:    newuser.email,
        password: newuser.password,
    }
    createnewuser.hashpassword(createnewuser.password)
    err := database.instance.create(&createnewuser)
    if err.error != nil {
        logrus.errorf("error saving food to the database: %s", err.error)
        return nil
    }

    return &createnewuser

}

问题是当我由于某种原因调用“finduserbyemail”时它无法序列化。

它一直有效，直到我引入枚举值集成。现在我收到上面的错误。

我的用户模型文件：

package models

import (
    "database/sql/driver"
    "golang.org/x/crypto/bcrypt"
    "gorm.io/gorm"
    "time"
)

type RoleAllowed string

const (
    admin   RoleAllowed = "admin"
    seller  RoleAllowed = "seller"
    rider   RoleAllowed = "rider"
    regular RoleAllowed = "regular"
)

func (st *RoleAllowed) Scan(value interface{}) error {
    *st = RoleAllowed(value.([]byte))
    return nil
}

func (st RoleAllowed) Value() (driver.Value, error) {
    return string(st), nil
}

type StatusAllowed string

const (
    suspended StatusAllowed = "suspended"
    active    StatusAllowed = "active"
    inactive  StatusAllowed = "inactive"
)

func (st *StatusAllowed) Scan(value interface{}) error {
    *st = StatusAllowed(value.([]byte))
    return nil
}

func (st StatusAllowed) Value() (driver.Value, error) {
    return string(st), nil
}

type User struct {
    ID              uint           `json:"id" gorm:"type:bigserial;primaryKey;autoIncrement"`
    Email           string         `json:"email" gorm:"type:varchar(255);unique;not null"`
    Password        string         `json:"password" gorm:"type:varchar(255);unique;not null""`
    OTPCode         int            `json:"otp_code"`
    Role            RoleAllowed    `json:"role" gorm:"type:role_allowed;default:'regular'"`
    Status          StatusAllowed  `json:"status" gorm:"type:status_allowed;default:'active'"`
    IsEmailVerified bool           `json:"isEmailVerified" gorm:"default:false"`
    OTPExpireTime   time.Time      `json:"otp_expire_time"`
    CreatedAt       time.Time      `json:"createdAt"`
    UpdatedAt       time.Time      `json:"updatedAt"`
    DeletedAt       gorm.DeletedAt `gorm:"index"`
}

func (u *User) HashPassword(password string) error {
    bytes, err := bcrypt.GenerateFromPassword([]byte(password), 14)
    if err != nil {
        return err
    }
    u.Password = string(bytes)
    return nil
}

func (u *User) CheckPasswordHash(password string) error {
    err := bcrypt.CompareHashAndPassword([]byte(u.Password), []byte(password))
    if err != nil {
        return err
    }
    return nil
}

请帮忙解决此问题？

正确答案

我编辑了下面的代码

package models

import (
    "database/sql/driver"
    "golang.org/x/crypto/bcrypt"
    "gorm.io/gorm"
    "time"
)

type RoleAllowed string

const (
    admin   RoleAllowed = "admin"
    seller  RoleAllowed = "seller"
    rider   RoleAllowed = "rider"
    regular RoleAllowed = "regular"
)

func (st *RoleAllowed) Scan(value interface{}) error {
    b, ok := value.([]byte)
    if !ok {
        *st = RoleAllowed(b)
    }
    return nil
}

func (st RoleAllowed) Value() (driver.Value, error) {
    return string(st), nil
}

type StatusAllowed string

const (
    suspended StatusAllowed = "suspended"
    active    StatusAllowed = "active"
    inactive  StatusAllowed = "inactive"
)

func (st *StatusAllowed) Scan(value interface{}) error {
    b, ok := value.([]byte)
    if !ok {
        *st = StatusAllowed(b)
    }
    return nil
}

func (st StatusAllowed) Value() (driver.Value, error) {
    return string(st), nil
}

type User struct {
    ID              uint           `json:"id" gorm:"type:bigserial;primaryKey;autoIncrement"`
    Email           string         `json:"email" gorm:"type:varchar(255);unique;not null"`
    Password        string         `json:"password" gorm:"type:varchar(255);unique;not null""`
    OTPCode         int            `json:"otp_code"`
    Role            RoleAllowed    `json:"role" gorm:"type:role_allowed;default:'regular'"`
    Status          StatusAllowed  `json:"status" gorm:"type:status_allowed;default:'active'"`
    IsEmailVerified bool           `json:"isEmailVerified" gorm:"default:false"`
    OTPExpireTime   time.Time      `json:"otp_expire_time"`
    CreatedAt       time.Time      `json:"createdAt"`
    UpdatedAt       time.Time      `json:"updatedAt"`
    DeletedAt       gorm.DeletedAt `gorm:"index"`
}

func (u *User) HashPassword(password string) error {
    bytes, err := bcrypt.GenerateFromPassword([]byte(password), 14)
    if err != nil {
        return err
    }
    u.Password = string(bytes)
    return nil
}

func (u *User) CheckPasswordHash(password string) error {
    err := bcrypt.CompareHashAndPassword([]byte(u.Password), []byte(password))
    if err != nil {
        return err
    }
    return nil
}

我必须检查类型，然后分配我需要的正确值。谢谢@mkopriva

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