在 go api 中收到错误消息以及结果

Question

我在 API 中有一条路线，我可以通过roles 获取用户。在这条路线中，如果我输入用户名，那么我将获得分配给他/她的所有roles。但问题是它只返回第一个结果。如果该角色存在于另一个对象中，则不会显示该角色。所以我对return 行发表评论，一切正常，但随着结果，我收到错误消息："user not found" 你们能告诉我我在做什么错误吗？
谢谢。
路线 -

GET("/users/:username", controllers.GetUserByRole)

控制器 -

func GetUserByRole(c *gin.Context) {
    paramId := c.Param("username")
    .............
    .............
    .............
    var newUsers []models.User
    iter := client.Collection("users").Documents(ctx)

    for {
        doc, err := iter.Next()
        if err == iterator.Done {
            break
        }
        if err != nil {
            log.Fatalf("Failed to iterate: %v", err)
        }

        var tempUsers models.User
        if err := doc.DataTo(&tempUsers); err != nil {
            break
        }
        newUsers = append(newUsers, tempUsers)
    }

    for _, a := range newUsers {
        for _, element := range a.Roles{
                if element == paramId {
            c.IndentedJSON(http.StatusOK, a)
            return     //if I comment this line line then I geting message `"user not found"` along with results
        }
    }
    }
    c.IndentedJSON(http.StatusNotFound, gin.H{"message": "user not found"})
}

网址：http://localhost:3000/users/Analyst
响应应该是：

  {
     "id": 1,
     "name": "Leanne Graham",
     "username": "Bret",
     "roles": ["Developer", "Analyst"],
  },
  {
    "id": 3,
    "name": "Clementine Bauch",
    "username": "Samantha",
    "roles": ["Manger", "Analyst"],
  }

但我是这样的（只有第一个匹配的）：

  {
     "id": 1,
     "name": "Leanne Graham",
     "username": "Bret",
     "roles": ["Developer", "Analyst"],
  }

如果我评论 return 行，那么响应是（期望的结果 + 错误消息）：

  {
     "id": 1,
     "name": "Leanne Graham",
     "username": "Bret",
     "roles": ["Developer", "Analyst"],
  },
  {
    "id": 3,
    "name": "Clementine Bauch",
    "username": "Samantha",
    "roles": ["Manger", "Analyst"],
  }{
    "message": "album not found"
}

完整的 API 响应 -

[
  {
     "id": 1,
     "name": "Leanne Graham",
     "username": "Bret",
     "roles": ["Developer", "Analyst"],
  },
  {
    "id": 2,
    "name": "Ervin Howell",
    "username": "Antonette",
    "roles": ["Assistant"],,
  },
  {
    "id": 3,
    "name": "Clementine Bauch",
    "username": "Samantha",
    "roles": ["Manger", "Analyst"],
  }
]

Answer 1

你可以这样做

var userList []models.User
for _, a := range newUsers {
    for _, element := range a.AssignedTo {
        if element == paramId {
            userList = append(userList, a)
        }
    }
}
if len(userList) == 0 {
     c.IndentedJSON(http.StatusNotFound, gin.H{"message": "user not found"})
     return
}

c.IndentedJSON(http.StatusOK, userList)

Answer 2

看起来你的 return 语句在你的 for 循环中，所以它找到第一个值并立即返回。当您将其注释掉时，您的函数不会返回，因此它成功完成，然后打印错误消息。将 return 语句移到两个 for 循环之外，应该没问题。此外，通过错误标志添加用于发送错误消息的逻辑。还建议使用 Manjeet Thakur 的替代解决方案。

func GetUserByRole(c *gin.Context) {
    paramId := c.Param("username")
    .............
    .............
    .............
    var newUsers []models.User
    iter := client.Collection("users").Documents(ctx)
 
    for {
        doc, err := iter.Next()
        if err == iterator.Done {
            break
        }
        if err != nil {
            log.Fatalf("Failed to iterate: %v", err)
        }
 
        var tempUsers models.User
        if err := doc.DataTo(&tempUsers); err != nil {
            break
        }
        newUsers = append(newUsers, tempUsers)
    }
    var errorflag := 1
    for _, a := range newUsers {
        for _, element := range a.AssignedTo {
                if element == paramId {
            c.IndentedJSON(http.StatusOK, a)
            errorflag := 0
                 //if I comment this line line then I geting message `"user not found"` along with results
        }
    }
    }
    if errorflag{
    c.IndentedJSON(http.StatusNotFound, gin.H{"message": "user not found"})
    }
    return
}