预期指向结构切片的指针

huangapple
go评论114阅读模式
英文:

Expected pointer to struct slice

问题

我正在使用golang编写一个服务器。

我有一个auth-helper，用安全令牌对用户进行身份验证（这只是一个测试）。当我在AuthUsingCredentials函数中进行查询时（我正在使用这个dep），它输出以下错误：

"Expected pointer to struct slice *[]struct"

如果我将var result *entities.User更改为var result []entities.User，然后打印result[0]，它可以工作，但是然后会输出：

"cannot use result[0] (type entities.User) as type *entities.User in argument to ah.userEntityToModel"

auth helper的代码：

auth.go

  1. package helpers
  3. import (
  4.   "fmt"
  6.   "server/data/entities"
  7.   "server/data/models"
  8.   "server/interfaces"
  9. )
  11. var AuthHelper *authHelper
  13. type authHelper struct{}
  15. func init() {
  16. 	AuthHelper = &authHelper{}
  17. }
  19. func (ah *authHelper) userEntityToModel(_entity *entities.User) (*models.User, error) {
  20.   u := models.NewUser(_entity, db)
  21. 	u.Username = _entity.Username
  23.   return u, nil
  24. }
  26. func (ah *authHelper) AuthenticateUsingCredentials(_token string) (interfaces.IUser, error) {
  27.   var result *entities.User
  28.   err := db.Where("Token", "=", _token).Find(result)
  29.   if err != nil {
  30.     return nil, err
  31.   }
  32.   if result == nil {
  33.     return nil, fmt.Errorf("Player '%s' not found", _token)
  34.   }
  36.   playerModel, err := ah.userEntityToModel(result)
  37.   if err != nil {
  38.     return nil, err
  39.   }
  41.   return playerModel, nil
  42. }
英文:

I'm working on a server in golang.

I have an auth-helper that authenticates the user with a secure token (its a test). The error comes when i make a query (I'm using this dep) in the AuthUsingCredentials function, it outputs the following error:

> "Expected pointer to struct slice *[]struct"

If I change the var result *entities.User for var result []entities.User and then print result[0] it works but then it outputs:

> "cannot use result[0] (type entities.User) as type *entities.User in
> argument to ah.userEntityToModel"

The auth helper code:

auth.go

  1. package helpers
  3. import (
  4.   "fmt"
  6.   "server/data/entities"
  7.   "server/data/models"
  8.   "server/interfaces"
  9. )
  11. var AuthHelper *authHelper
  13. type authHelper struct{}
  15. func init() {
  16. 	AuthHelper = &authHelper{}
  17. }
  19. func (ah *authHelper) userEntityToModel(_entity *entities.User) (*models.User, error) {
  20.   u := models.NewUser(_entity, db)
  21. 	u.Username = _entity.Username
  23.   return u, nil
  24. }
  26. func (ah *authHelper) AuthenticateUsingCredentials(_token string) (interfaces.IUser, error) {
  27.   var result *entities.User
  28.   err := db.Where("Token", "=", _token).Find(result)
  29.   if err != nil {
  30.     return nil, err
  31.   }
  32.   if result == nil {
  33.     return nil, fmt.Errorf("Player '%s' not found", _token)
  34.   }
  36.   playerModel, err := ah.userEntityToModel(result)
  37.   if err != nil {
  38.     return nil, err
  39.   }
  41.   return playerModel, nil
  42. }

答案1

得分: 0

应该可以这样做。

  1. func (ah *authHelper) AuthenticateUsingCredentials(_token string) (interfaces.IUser, error) {
  2.   var result []entities.User
  3.   err := db.Where("Token", "=", _token).Find(&result)
  4.   if err != nil {
  5.     return nil, err
  6.   }
  7.   if len(result) <= 0 {
  8.     return nil, fmt.Errorf("Player '%s' not found", _token)
  9.   }
  11.   playerModel, err := ah.userEntityToModel(&result[0])
  12.   if err != nil {
  13.     return nil, err
  14.   }
  16.   return playerModel, nil
  17. }

你试图将一个用户切片放入一个接受单个用户指针的函数中。

英文:

Something like this should work.

  1. func (ah *authHelper) AuthenticateUsingCredentials(_token string) (interfaces.IUser, error) {
  2.   var result *[]entities.User
  3.   err := db.Where(&quot;Token&quot;, &quot;=&quot;, _token).Find(result)
  4.   if err != nil {
  5.     return nil, err
  6.   }
  7.   if len(result) &lt;= 0 {
  8.     return nil, fmt.Errorf(&quot;Player &#39;%s&#39; not found&quot;, _token)
  9.   }
  11.   playerModel, err := ah.userEntityToModel(&amp;(*result)[0])
  12.   if err != nil {
  13.     return nil, err
  14.   }
  16.   return playerModel, nil
  17. }

you are trying to put an slice of users in a function that takes a pointer to a single user.

huangapple
  • 本文由 发表于 2015年4月26日 06:17:53
  • 转载请务必保留本文链接：https://go.coder-hub.com/29871354.html
  • go
  • struct
  • types
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确定