Cannot retrieve "_id" value using mgo with golang

Question

This is my struct definition: ``` type Article struct { Id bson.ObjectId `json:"id" bson:"_id,omitempty"` Title string `json:"title"` Author string `json:"author"` Date string `json:"date"` Tags string `json:"tags"` Content string `json:"content"` Status string `json:"status"` } ``` This is the method I get my data from database: ``` func AllArticles() []Article { articles := []Article{} err := c_articles.Find(bson.M{}).All(&articles) if err != nil { panic(err) } return articles } ``` This is one piece of object stored in database: ``` { "_id" : ObjectId( "5281b83afbb7f35cb62d0834" ), "title" : "Hello1", "author" : "DYZ", "date" : "2013-11-10", "tags" : "abc", "content" : "This is another content.", "status" : "published" } ``` This is the printed result: ``` [{ObjectIdHex("") Hello1 DYZ 2013-11-10 abc This is another content. published} {ObjectIdHex("") Hello2 DYZ 2013-11-14 abc This is the content. published}] ``` It seems that I can't get the real value of `_id` field, it's always…

Accepted Answer

I've found the problem.

In the code:

```
Id      bson.ObjectId `json:"id"        bson:"_id,omitempty"`
```

between `json:` and `bson:`, I used a `tab` instead of `space` so the problem occurs. If I change this line of code to:

```
Id      bson.ObjectId `json:"id" bson:"_id,omitempty"`
```

With one `space` between `json:` and `bson:`, it turns out to work just fine.

Cannot retrieve "_id" value using mgo with golang

Solution

Problem