如何防止mgo将int编组为float64

Question

I have unknown json structure data stored in mongodb. They have the fields to present the unix time like this:

"date": 1424803567,

I am using mgo to load them to the bson.M.

var result bson.M
iter := c.Find(q).Iter()
for iter.Next(&result) {

Those unix time fields have turned to the fload64 instead of the int.

 "date": 1.424728798e+09,

So, how to prevent that happens in the case above? thanks!

Answer 1

Mgo does not unmarshal an integer to a float unless destination value is explicitly typed as a float by the application. Mgo is returning a float value here because the value stored in the database is a float.

You can unmarshal the float value to an integer by specifying the type using a struct:

var result struct {
  Date int64 `bson:"date"`
}
for iter.Next(&result) {
  ...
}