我实际上是在学习围棋，按照一些教程作为这个 one构建 Resftul API 应用程序。

第一次使用 Go 和 mongoDB，我不太了解如何在我的集合中的某个文档中获取特定的键。

实际上我有这个对象模型:

type Numobject struct {
    ID     bson.ObjectId `bson:"_id" json:"id"`
    Text   string        `bson:"text" json:"text"`
    Number int           `bson:"number" json:"number"`
    Found  bool          `bson:"found" json:"found"`
    Type   string        `bson:"type" json:"type"`
}

我可以使用此功能通过 ID 获得特定对象:

// Find Object by ID
func (m *NumObjectDAO) FindByNumber(id string) (Numobject, error) {
    var numObject Numobject
    err := db.C(COLLECTION).FindId(bson.ObjectIdHex(id)).One(&numObject)
    return numObject, err
}

我在main.go中调用我的方法如下

package main

import (
    "encoding/json"
    "log"
    "net/http"

    "github.com/gorilla/mux"
    "gopkg.in/mgo.v2/bson"

    . "github.com/sandaleRaclette/03-coddingChallenge/config"
    . "github.com/sandaleRaclette/03-coddingChallenge/dao"
    . "github.com/sandaleRaclette/03-coddingChallenge/models"
)

// Save the configuration of mongodatabase (localhost and which db use) in Config array
var config = Config{}
var dao = NumObjectDAO{}

// GET list of all objects
func AllObjectsEndPoint(w http.ResponseWriter, r *http.Request) {
    movies, err := dao.FindAll()
    if err != nil {
        respondWithError(w, http.StatusInternalServerError, err.Error())
        return
    }
    respondWithJson(w, http.StatusOK, movies)
}

// GET an Object by its ID
func FindObjectEndpoint(w http.ResponseWriter, r *http.Request) {
    params := mux.Vars(r)
    numObject, err := dao.FindByNumber(params["number"])
    if err != nil {
        respondWithError(w, http.StatusBadRequest, "Invalid Object ID")
        return
    }
    respondWithJson(w, http.StatusOK, numObject)
}

//  Respond Methods
func respondWithError(w http.ResponseWriter, code int, msg string) {
    respondWithJson(w, code, map[string]string{"error": msg})
}

func respondWithJson(w http.ResponseWriter, code int, payload interface{}) {
    response, _ := json.Marshal(payload)
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(code)
    w.Write(response)
}

// Parse the configuration file 'config.toml', and establish a connection to DB
func init() {
    config.Read()

    dao.Server = config.Server
    dao.Database = config.Database
    dao.Connect()
}

// Define HTTP request routes and define the differents endpoints
func main() {
    r := mux.NewRouter()
    r.HandleFunc("/api/v1/trivia", AllObjectsEndPoint).Methods("GET")
    r.HandleFunc("/api/v1/trivia/{number}", FindObjectEndpoint).Methods("GET")

    if err := http.ListenAndServe(":3000", r); err != nil {
        log.Fatal(err)
    }
}

除了通过ID获取对象还有其他方法吗？如何根据我的模型获取具有特定键的对象作为 Number 或 Type ？

我想在 GET "/api/v1/trivia/45000000"时得到这样的东西:

{
        "id": "5aa554c89d63b0d3580449a5",
        "text": "45000000 is the number of turkeys Americans eat at Thanksgiving annually.",
        "number": 45000000,
        "found": true,
        "type": "trivia"
    }

我实际上在寻找 here对于一些答案，但我在查询时遇到了一些困难......如果有人可以给我初学者解释......

最佳答案

使用Find一般queries :

err := db.c(COLLECTION).Find(bson.D{{"Number", 10}}).One(&numobjecct)

关于database - 按特定字段获取对象，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49225624/