mgo example

mgoExample.go

package main

import (
	"fmt"
	"labix.org/v2/mgo"
	"labix.org/v2/mgo/bson"
	"time"
)

type Person struct {
	ID        bson.ObjectId `bson:"_id,omitempty"`
	Name      string
	Phone     string
	Timestamp time.Time
}

var (
	IsDrop = true
)

func main() {
	session, err := mgo.Dial("127.0.0.1")
	if err != nil {
		panic(err)
	}

	defer session.Close()

	session.SetMode(mgo.Monotonic, true)

	// Drop Database
	if IsDrop {
		err = session.DB("test").DropDatabase()
		if err != nil {
			panic(err)
		}
	}

	// Collection People
	c := session.DB("test").C("people")

	// Index
	index := mgo.Index{
		Key:        []string{"name", "phone"},
		Unique:     true,
		DropDups:   true,
		Background: true,
		Sparse:     true,
	}

	err = c.EnsureIndex(index)
	if err != nil {
		panic(err)
	}

	// Insert Datas
	err = c.Insert(&Person{Name: "Ale", Phone: "+55 53 1234 4321", Timestamp: time.Now()},
		&Person{Name: "Cla", Phone: "+66 33 1234 5678", Timestamp: time.Now()})

	if err != nil {
		panic(err)
	}

	// Query One
	result := Person{}
	err = c.Find(bson.M{"name": "Ale"}).Select(bson.M{"phone": 0}).One(&result)
	if err != nil {
		panic(err)
	}
	fmt.Println("Phone", result)

	// Query All
	var results []Person
	err = c.Find(bson.M{"name": "Ale"}).Sort("-timestamp").All(&results)

	if err != nil {
		panic(err)
	}
	fmt.Println("Results All: ", results)

	// Update
	colQuerier := bson.M{"name": "Ale"}
	change := bson.M{"$set": bson.M{"phone": "+86 99 8888 7777", "timestamp": time.Now()}}
	err = c.Update(colQuerier, change)
	if err != nil {
		panic(err)
	}

	// Query All
	err = c.Find(bson.M{"name": "Ale"}).Sort("-timestamp").All(&results)

	if err != nil {
		panic(err)
	}
	fmt.Println("Results All: ", results)

}

My Observation about UpdateAll() is, by default it upserts the record..
that means, if "phone" field from the change is not present in record, it will insert the field

change:= bson.M{"$set":bson.M{"phone": "+86 99 8888 7777", "timestamp": time.Now()}}

Is there a way to override the default upsert behaviour of UpdateAll() call ?

You can also do

if err := c.Update(colQuerier, change); err != nil {
  // panic(err) <-- one way, or:
  w.WriteHeader(404)
  return
}

Hi All,
I am trying to access the record but its returning me empty record
code:
result := Person{}

	err = c.Find(bson.M{"first_name": "ABC"}).Select(bson.M{"userEmail": 1}).One(&result)
	if err != nil {
		panic(err)
	}
	fmt.Println("Email", result)

output :
Email { }

please help.

Thanks for posting... learnt a lot..

Please is there a way to chain queries??? like where firstname is "anything" and lastname is "anything as well"

Thanks

Thanks a lot

thanks

how to connect mongodb+srv ?

Hi guys,
If i have probably 4 server of mongodb. 1 server active(main), and the others server are slave which the active(main) server somehow can switch as slave, and slave can switch as active(main) automatic . how i develop the code to get only the active(main) server only? active(main) server means you can do add, remove, find process in that server only. Thanks before.

Checkout this : https://docs.mongodb.com/manual/reference/method/db.currentOp/

it would be so nice if we could pass a golang struct in the find method (the same struct which we inserted).

thanks for this