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Select column from Mongodb in golang using mgo

Tags:

mongodb

go

mgo

As I know, we can use

> db['twitter-3'].find({}, {"text": 1})

to select all texts in collection.

How can we use mgo to find specific field in golang? I tried

var result []string
err = conn.Find(bson.M{}, bson.M{"text", 1}).All(&result)

But it is not correct.

like image 218
Wyatt Avatar asked Jun 29 '15 13:06

Wyatt


2 Answers

Use the query Select method to specify the fields to return:

var result []struct{ Text string `bson:"text"` }
err := c.Find(nil).Select(bson.M{"text": 1}).All(&result)
if err != nil {
    // handle error
}
for _, v := range result {
     fmt.Println(v.Text)
}

In this example, I declared an anonymous type with the one selected field. It's OK to use a type with all document fields.

like image 197
Bayta Darell Avatar answered Oct 25 '22 02:10

Bayta Darell


to select multiple fields:

var result []struct{
    Text string `bson:"text"`
    Otherfield string `bson:"otherfield"`
}

err := c.Find(nil).Select(bson.M{"text": 1, "otherfield": 1}).All(&result)
if err != nil {
   // handle error
}
for _, v := range result {
    fmt.Println(v.Text)
}
like image 2
drrzmr Avatar answered Oct 25 '22 04:10

drrzmr