$gt 大于 $exists 存在 $lt

if err := u.Find(bson.M{"registertime": bson.M{"$gt": 0}}).All(&res.Players); err == nil {

}

if err := c.Find(bson.M{"roomcard": bson.M{"$exists": true}}).All(&res.Allqzchange); err == nil {
}

start := time.Unix(msg.TimeStart, 0).Format("2006-01-02 15:04:05")
end := time.Unix(msg.TimeEnd, 0).Format("2006-01-02 15:04:05")
if err := u.Find(bson.M{"registertime": bson.M{"$gt": start, "$lt": end}}).All(&res.Typeplayers); err == nil {
log.Info("----区间----:", res.Typeplayers)
}