我应该如何使用mgo处理UUID字段? [英] How should I handle UUID fields using mgo?

问题描述

我在MongoDB中有此文档:

I have this Document in MongoDB:

{
    "_id": {
        "$oid": "5ad0873b169ade0001345d34"
    },
    "j": {
        "$uuid": "94482b86-1005-e3a0-5235-55fb7c1d648a"
    },
    "v": "sign",
    "d": "a",
    "s": "init",
    "response": {},
    "creation_date": {
        "$date": "2018-04-13T10:32:27.140Z"
    }
}

我要过滤&使用mgo在Golang中获取一些文档，这是我的代码:

I want to filter & fetch some documents in Golang using mgo, and here's my code:

package main

import (
    "fmt"
    "log"
    "time"
    "gopkg.in/mgo.v2"
    "gopkg.in/mgo.v2/bson"
)

type JOB struct {
   ID               bson.ObjectId       `bson:"_id,omitempty"`
   Key          string              `bson:"j"`
   Svc              string              `bson:"v"`
   DocType          string              `bson:"d"`
   Status           string              `bson:"s"`
   CreationDate     time.Time           `bson:"creation_date"`
}

func main() {
    session, err := mgo.Dial("mongodb://...")
    if err != nil {
            log.Fatal(err)
    }
    defer session.Close()
    c := session.DB("main").C("job")

    var results []JOB
    e := c.Find(bson.M{"v": "sign"}).All(&results)
    if e != nil {
        log.Fatal(e)
    }
    for _, job := range results[:5] {
        fmt.Println(job.ID, job.Key, job.Svc, job.DocType, job.Status, job.CreationDate)

    }

}

这是我运行程序时的输出:

Here's the output when I run my program:

ObjectIdHex("5acf91e0269c650001a82683")  sign a ok 2018-04-12 19:05:36.294 +0200 CEST
ObjectIdHex("5ad0873b169ade0001345d34")  sign a init 2018-04-13 12:32:27.14 +0200 CEST
ObjectIdHex("5ad0873e169ade0001345d36")  sign a init 2018-04-13 12:32:30.852 +0200 CEST
ObjectIdHex("5ad08742169ade0001345d38")  sign a init 2018-04-13 12:32:34.478 +0200 CEST
ObjectIdHex("5ad087492e083b00013a862a")  sign a init 2018-04-13 12:32:41.577 +0200 CEST

问题:

job.Key(MongoDB Document中的j字段是uuid)保持为空.我也尝试过"github.com/satori/go.uuid"，但无法弄清楚.

job.Key (j field in MongoDB Document which is a uuid) remains empty. I've tried also "github.com/satori/go.uuid" but I couldn't figure it out.

所以我想知道如何处理该uuid字段，更一般地讲如何调试此问题.在Go中完成新手培训.

So I would like to know how to handle that uuid field, and more generally how to debug this problem. Complete newbie in Go.

例如，在python中，我可以获得一个文档，而在doc._data中，我可以看到该文档的所有字段，在Go中是否有等效的方法?

For example in python I could get a Document and using doc._data I could see all fields of that document, is there a equivalent way of doing this in Go?

更新

我尝试将Key设置为bson.Raw，我看到了一些字节，但是无法将它们转换为uuid:

I tried to set Key as bson.Raw, I see some bytes, but cannot convert them to uuid:

fmt.Println(job.Key)
u := uuid.FromBytesOrNil(job.Key.Data)
fmt.Println(u)

输出:

{5 [16 0 0 0 3 160 227 5 16 134 43 72 148 138 100 29 124 251 85 53 82]}
00000000-0000-0000-0000-000000000000

推荐答案

感谢@Thomas，我发现我正在使用0x05 Kind获取bin数据.

Thanks to @Thomas I've figured out that I'm getting bin data with 0x05 Kind.

所以我将Job结构更改为:

Key             bson.Binary         `bson:"j"`

在执行查询后，我将这样的二进制数据解组:

and after doing query, I unmarshal that binary data like this:

import "github.com/satori/go.uuid"

var Ids []uuid.UUID

for _, job := range results {
    u, err := uuid.FromBytes(job.Key.Data)
    if err != nil {
        panic(err)
    }
    Ids = append(Ids, u)
}

所以现在在Job.Key.Data中，根据

So now in Job.Key.Data I have binary version of UUID according to this documentation.

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