I am working on a project that uses combination of Go and MongoDB. I am stuck at a place where I have a struct like:
type Booking struct {
// booking fields
Id int `json:"_id,omitempty" bson:"_id,omitempty"`
Uid int `json:"uid,omitempty" bson:"uid,omitempty"`
IndustryId int `json:"industry_id,omitempty" bson:"industry_id,omitempty"`
LocationId int `json:"location_id,omitempty" bson:"location_id,omitempty"`
BaseLocationId int `json:"base_location_id,omitempty" bson:"base_location_id,omitempty"`
}
In this struct, the field Id
is of int
type. But as we know MongoDB's default id is of bsonObject
type. Some times, the system generates the default MongoDB id in Id
field.
To overcome this I have modified the struct like this:
type Booking struct {
// booking fields
Id int `json:"_id,omitempty" bson:"_id,omitempty"`
BsonId bson.ObjectId `json:"bson_id" bson:"_id,omitempty"`
Uid int `json:"uid,omitempty" bson:"uid,omitempty"`
IndustryId int `json:"industry_id,omitempty" bson:"industry_id,omitempty"`
LocationId int `json:"location_id,omitempty" bson:"location_id,omitempty"`
BaseLocationId int `json:"base_location_id,omitempty" bson:"base_location_id,omitempty"`
}
In above struct, I have mapped the same _id
field in two different struct fields Id (type int) and BsonId
(type bson.ObjectId
). I want if id of integer type comes, it maps under Id
otherwise under BsonId
.
But this thing is giving following error:
Duplicated key '_id' in struct models.Booking
How can I implement this type of thing with Go Structs ??
Update:
Here is the code I have written for custom marshaling/unmarshaling:
func (booking *Booking) SetBSON(raw bson.Raw) (err error) {
type bsonBooking Booking
if err = raw.Unmarshal((*bsonBooking)(booking)); err != nil {
return
}
booking.BsonId, err = booking.Id
return
}
func (booking *Booking) GetBSON() (interface{}, error) {
booking.Id = Booking.BsonId
type bsonBooking *Booking
return bsonBooking(booking), nil
}
But this is giving type mismatch error of Id and BsonId fields. What should I do now ?