使Sort（）在MongoDB查询中工作

Question

Here I'm Sorting my data using the sort() but it not works well. Below I posted my code and output too:-

Code:-

1. Struct declared

   import(
    "github.com/gin-gonic/gin"
    "gopkg.in/mgo.v2/bson"
    "strconv"
    "fmt"
    "time"
    "gopkg.in/mgo.v2"// for db
   )  
   type Schedule struct{
    Id           int                 `json:"_id" bson:"_id"`
    Day          string              `form:"day" json:"day" bson:"day"`
    StartDate    int64               `form:"start_date" json:"start_date" bson:"start_date"`
    EndDate      int64                `form:"end_date" json:"end_date" bson:"end_date"`
    StartTime    int64                `form:"start_time" json:"start_time" bson:"start_time"`
    EndTime      int64               `form:"end_time" json:"end_time" bson:"end_time"`
   }
   type Schedules []Schedule  
   

2. Database functions

   func GetSchedulingListing(Query interface{}) (result Schedules, err error) {
    mongoSession := ConnectDb()
    sessionCopy := mongoSession.Copy()
    defer sessionCopy.Close()
    getCollection := mongoSession.DB("schedule2").C("schedule")
    err = getCollection.Find(Query).Select(bson.M{"start_date": 1, "end_date": 1}).Sort("start_date").All(&result)
    if err != nil {
      return result, err
    }
    return result, nil
   }
   
   func GetSchedule(c *gin.Context) {
    selected_day:= "Monday"
    conditions := bson.M{"day":selected_day}
    data, err := models.GetSchedulingListing(conditions) 
    for i := range data {
       start_date := data[i].StartDate
       end_date := data[i].EndDate
       days:= time.Unix(end_date,0).Sub(time.Unix(start_date,0)).Hours() / 24
       for i := 1; i <= int(days+1); i++ {
          if selected_day == time.Unix(start_date,0).Weekday().String() {
            fmt.Println(start_date)
          }
        start_date = start_date + 86400
       }
     }
   }
   

In the above code I'm using Sort("start_date") in query function GetSchedulingListing. But it not works well it prints the output like:-

Output:-

 1525651200
 1526256000
 1526860800
 1527465600
 1525651200
 1526256000
 1526860800
 1527465600

Expected output:-

 1525651200
 1525651200
 1526256000
 1526256000
 1526860800
 1526860800
 1527465600
 1527465600

Database record:-

{
 "_id" : 1,
 "day" : "Monday",
 "start_date" : NumberLong(1525132800),
 "end_date" : NumberLong(1527638400),
 "start_time" : NumberLong(22800),
 "end_time" : NumberLong(30000)
}
{
 "_id" : 2,
 "day" : "Monday",
 "start_date" : NumberLong(1525132800),
 "end_date" : NumberLong(1527638400),
 "start_time" : NumberLong(12000),
 "end_time" : NumberLong(19200)
}

Data retrieved by the Query

[{1  1525132800 1527638400 0 0} {2  1525132800 1527638400 0 0}]
 // because I'm using the `.Select(bson.M{"start_date": 1, "end_date": 1})` 

Can anyone tell whats the problem there why I'm not getting my Expected Output. Thank you.