error updating an edge value (delete/set) in same request

[cesardevera]

hi,

I'm trying to update an edge value by deleting it and the setting it with a new value, in the same request, using the Go client.

it seems that the delete is not working.

here is my test code:
teste2.go.txt

[pawanrawal]

@cesardevera Thanks for the detailed code example which helped reproduce and understand the issue immediately. It would work if you did

e = usrnode.Edge("profile")
e.SetValueString("admin")
req.Delete(e)

That is you have to give the current value of the edge. Infact req.Delete(e) gives an error, which you should check. Though, it should be possible to delete the edge without knowing the value, like S P *. Right now you can do that through a raw mutation.

	req.SetQuery(fmt.Sprintf(`mutation {
		delete {
			<%s> <profile> * .
		}
	}`, usrnode))

	resp, err = dgraphClient.Run(context.Background(), &req)
	req.SetQuery(fmt.Sprintf(`mutation {
		set {
			<%s> <profile> "root" .
		}
	}`, usrnode))

I will add helper functions to the client for doing S P * and S * * deletion.

[cesardevera]

hum... I understood what you said, but I tried the changes and they still didn't work,

could it be a version issue? I'm using:

./dgraph --config config.yaml

Dgraph version   : v0.8.0
Commit SHA-1     : 5e6d0192
Commit timestamp : 2017-07-18 21:52:22 +1000
Branch           : HEAD

I modified my test file in two versions: on that uses mutations and the other that sets the string value, and in both, I separated the delete request from the new set request.

anyway, the output is the same:

dgraph % go run teste2-setValueString.go 
Query1: [{UID:8002 Email:[email protected] Profile:admin}]

error is <nil>
Query2: [{UID:8002 Email:[email protected] Profile:admin} {UID:8002 Email:[email protected] Profile:root}]

8002
8002

dgraph % go run teste2-mutation.go      
Query1: [{UID:9002 Email:[email protected] Profile:admin}]

error is <nil>
Query2: [{UID:9002 Email:[email protected] Profile:admin} {UID:9002 Email:[email protected] Profile:root}]

9002
9002

I attached my tests too.

teste2-mutation.go.txt
teste2-setValueString.go.txt

[pawanrawal]

This is a bug with the Unmarshal function. It is related to passing the same var r Res to Unmarshal multiple times. It just keeps on appending to r.Root. So even though the server second-time returns only one user with Profile as root (can be verified by doing request through http), Unmarshal appends it to the already existing user value with Profile admin.

This is different from how json.Unmarshal behaves, hence I would consider it as a bug and will submit a fix. In the meantime, if you were to clear the Res object as shown in the file on line 113 you won't see this issue.

main.go.txt

[cesardevera]

solved! thanks :D