# Updating graph using struct with uid makes edges disappear

**URL:** <https://discuss.dgraph.io/t/updating-graph-using-struct-with-uid-makes-edges-disappear/8122>\
**Category:** Dgraph Clients\
**Tags:** dgo, untagged\
**Created:** [July 6, 2020, 9:15am UTC](https://discuss.dgraph.io/t/updating-graph-using-struct-with-uid-makes-edges-disappear/8122 "2020-07-06T09:15:38Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![diggy](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/diggy/32/3666_2.png) [@diggy](https://discuss.dgraph.io/u/diggy)\
**Post date:** [July 6, 2020, 9:15am UTC](https://discuss.dgraph.io/t/updating-graph-using-struct-with-uid-makes-edges-disappear/8122/1 "2020-07-06T09:15:38Z")

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**Moved from GitHub [dgo/130](https://github.com/dgraph-io/dgo/issues/130)**

_Posted by_ [AugustDev](https://github.com/AugustDev):

I am creating a node by serializing struct and feeding to dgraph. Then I would like to update a value node of the graph by building go struct again and providing it with node UID. Even though update is successful, some edges have disappeared.

Dgo go [documentation](https://godoc.org/github.com/dgraph-io/dgo#example-package--SetObject) says `While setting an object if a struct has a Uid then its properties in the graph are updated else a new node is created.`

I am providing code which:

1. Creates `User` with `FavQuote`, `FavCar` and Contact details. (All good)
2. Knowing UID of `User` I update `FavQuote`. (`FavQuote` updated, `FavCar` remains, however edge to Contact details disappeared)

I had no problems with such node updates before, however this time the struct is more deeply nested.

```auto
package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"

	"github.com/dgraph-io/dgo/v200"
	"github.com/dgraph-io/dgo/v200/protos/api"
	"google.golang.org/grpc"
)

// User -
type User struct {
	UID string `json:"uid,omitempty"`
	DType []string `json:"dgraph.type,omitempty"`
	FavQuote string `json:"quote,omitempty"`
	FavCar string `json:"car,omitempty"`
	ContactDetails UserContactDetails `json:"user.contact_details,omitempty"`
}

// UserContactDetails -
type UserContactDetails struct {
	UID string `json:"uid,omitempty"`
	DType []string `json:"dgraph.type,omitempty"`
	Mobile PhoneNumber `json:"contact_details.mobile,omitempty"`
}

// PhoneNumber -
type PhoneNumber struct {
	UID string `json:"uid,omitempty"`
	DType []string `json:"dgraph.type,omitempty"`
	CountryCode string `json:"phone.country_code,omitempty"`
	NationalNumber string `json:"phone.national_number,omitempty"`
}

func main() {
	conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
	if err != nil {
		log.Fatal(err)
	}
	defer conn.Close()
	dg := dgo.NewDgraphClient(api.NewDgraphClient(conn))

	u := User{
		UID: "_:newUser",
		DType: []string{"User"},
		FavQuote: "Moon",
		FavCar: "Lambo",
		ContactDetails: UserContactDetails{
			DType: []string{"ContactDetails"},
			Mobile: PhoneNumber{
				DType: []string{"PhoneNumber"},
				CountryCode: "+33",
				NationalNumber: "98766543",
			},
		},
	}

	op := &api.Operation{}
	op.Schema = `
		<phone.country_code>: string @index(exact) .
		<phone.national_number>: string @index(exact) .
		<quote>: string .
		<car>: string .

		type User {
			quote
			car
			user.contact_details: ContactDetails
		}

		type ContactDetails {
			contact_details.mobile: PhoneNumber
		}

		type PhoneNumber {
			phone.country_code
			phone.national_number
		}
	`

	ctx := context.Background()
	if err := dg.Alter(ctx, op); err != nil {
		log.Fatal(err)
	}

	// CREATING USER
	mu := &api.Mutation{
		CommitNow: true,
	}

	ub, err := json.Marshal(u)
	if err != nil {
		log.Fatal(err)
	}

	mu.SetJson = ub
	response, err := dg.NewTxn().Mutate(ctx, mu)
	if err != nil {
		log.Fatal(err)
	}

	uid := response.Uids["newUser"]
	fmt.Println("UID: " + uid)

	// User correctly created with all details and can be verified in Ratel

	// MODIFYING USER
	u = User{
		UID: uid,
		FavQuote: "Jupiter",
	}

	mu = &api.Mutation{
		CommitNow: true,
	}

	ub, err = json.Marshal(u)
	if err != nil {
		log.Fatal(err)
	}

	mu.SetJson = ub
	_, err = dg.NewTxn().Mutate(ctx, mu)
	if err != nil {
		log.Fatal(err)
	}

	// User updated `FavQuote`. "FavCar" remains however contact details edge from user have dissapeared !?
}

```

To check data in Ratel I use

```auto
{
  u(func: uid(0x2a85)) {
    uid
    quote
    car
    user.contact_details {
      contact_details.mobile {
        phone.country_code
        phone.national_number
      }
    }
  }
}

```

Graph before modifying user

```json
      {
        "uid": "0x2a85",
        "quote": "Moon",
        "car": "Lambo",
        "user.contact_details": {
          "contact_details.mobile": {
            "phone.country_code": "+33",
            "phone.national_number": "98766543"
          }
        }
      }

```

Graph after modifying user

```json
      {
        "uid": "0x2a85",
        "quote": "Jupiter",
        "car": "Lambo"
      }

```

Which no longer has contact details 🤷‍♂️

---

<div class="post-metadata">

**Author:** ![diggy](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/diggy/32/3666_2.png) [@diggy](https://discuss.dgraph.io/u/diggy)\
**Post date:** [July 7, 2020, 11:39am UTC](https://discuss.dgraph.io/t/updating-graph-using-struct-with-uid-makes-edges-disappear/8122/2 "2020-07-07T11:39:27Z")

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[AugustDev](https://github.com/AugustDev) _commented_ :

Aaa solved. Someone pointed out that problem was because of the way Go serialiazes structs. I had to replace `UserContactDetails` to `* UserContactDetails` and it all works. Thank you kind stranger

---

<div class="post-metadata">

**Author:** ![diggy](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/diggy/32/3666_2.png) [@diggy](https://discuss.dgraph.io/u/diggy)\
**Post date:** [July 11, 2020, 3:56am UTC](https://discuss.dgraph.io/t/updating-graph-using-struct-with-uid-makes-edges-disappear/8122/3 "2020-07-11T03:56:36Z")

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