Insert data in MongoDB using mgo - mongodb

Question

I'm trying to insert some data in MongoDB using mgo but the outcome is not what I wanted.
My struct
type Slow struct {
Endpoint string
Time string
}
My insert statement
err := collection.Insert(&Slow{endpoint, e})
if err != nil {
panic(err)
}
How I'm trying to print it
var results []Slow
err := collection.Find(nil).All(&results)
if err != nil {
panic(err)
}
s, _ := json.MarshalIndent(results, " ", " ")
w.Write(s)
My output (Marshaled JSON)
[{
"Endpoint": "/api/endpoint1",
"Time": "0.8s"
},
{
"Endpoint": "/api/endpoint2",
"Time": "0.7s"
}]
What I wanted
{
"/api/endpoint1":"0.8s",
"/api/endpoint2":"0.7s"
}
//No brackets
Thank you.

Answer 1

First, you seem to want the results sorted by Endpoint. If you don't specify any sort order when querying, you can have no guarantee of any specific order. So query them like this:
err := collection.Find(nil).Sort("endpoint").All(&results)
Next, what you want is not the JSON representation of the results. To get the format you want, use the following loop:
w.Write([]byte{'{'})
for i, slow := range results {
if i > 0 {
w.Write([]byte{','})
}
w.Write([]byte(fmt.Sprintf("\n\t\"%s\":\"%v\"", slow.Endpoint, slow.Time)))
}
w.Write([]byte("\n}"))
Output is as you expect it (try it on the Go Playground):
{
"/api/endpoint1":"0.8s",
"/api/endpoint2":"0.7s"
}