# @id and @hasinverse on specific type **URL:** \ **Category:** Dgraph\ **Tags:** dgo, dgraph\ **Created:** [April 3, 2021, 1:05pm UTC](https://discuss.dgraph.io/t/id-and-hasinverse-on-specific-type/13530 "2021-04-03T13:05:54Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![lzr](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/lzr/32/7493_2.png) [@lzr](https://discuss.dgraph.io/u/lzr)\ **Post date:** [April 3, 2021, 1:05pm UTC](https://discuss.dgraph.io/t/id-and-hasinverse-on-specific-type/13530/1 "2021-04-03T13:05:55Z")
Hello, I’m trying to build an app with golang and dgraph, and I’m unable to make a @id working with @hasInverse I’m using the following Schema : ```auto type Account { email: String! @id @search(by: [hash, regexp]) sessions: [Session] @hasInverse(field: account) } type Session { id: ID! account: Account! @hasInverse(field: sessions) mail_to: String! @search(by: [hash, regexp]) mail_from: String! @search(by: [hash, regexp]) mail_text: String! mail_html: String! mail_subject: String! @search(by: [hash, regexp]) mail_original: String! } ``` An account is identified by it’s email (so there should be only one object with the same mail address … In my case, I can insert several time the SAME mail address and have a different object …) A session belong to a user and should be reversed in the account’s sessions array My golang mapping for this, is the following: ```auto type Account struct { Email string `json:"Account.email,omitempty"` Sessions []Session `json:"Account.sessions,omitempty"` DType []string `json:"dgraph.type,omitempty"` } type Session struct { ID string `json:"Account.id,omitempty"` MailTo string `json:"Session.mail_to,omitempty"` MailFrom string `json:"Session.mail_from,omitempty"` MailText string `json:"Session.mail_text,omitempty"` MailHTML string `json:"Session.mail_html,omitempty"` MailSubject string `json:"Session.mail_subject,omitempty"` MailOriginal string `json:"Session.mail_original,omitempty"` CreatedAt time.Time `json:"Session.created_at,omitempty"` Account Account `json:"Session.account,omitempty"` DType []string `json:"dgraph.type,omitempty"` } ``` If I use the name without the Session or the Account, it create other predicates … so is this the correct way to use dedicated types in golang ? My code to insert my object is the following : ```auto pb, err := json.Marshal(data.Session{ CreatedAt: time.Now(), MailTo: "test2@test.com", MailFrom: "mf@rlol2.com", MailText: "text222", DType: []string{"Session"}, Account: data.Account{Email: "test2test@test.com", DType: []string{"Account"}}, }) mu := &api.Mutation{SetJson: pb,CommitNow: true} if res, err := dg.NewTxn().Mutate(ctx, mu); err != nil {...} ``` My questions are : - In theory, if I insert an account, the email **is the only id** (when i’m querying dgraph, I always end up with **uid that are generated** … is that normal? so in my case if I create several time an account with the SAME email I end up with several time the SAME email in dgraph … with the @id there sshould be only one no ?) - If I create a session with an account linked to it, when I query that account, I’m suppose to get an array of session ? in my case when I request account, I don’t get the array of sessions : ```auto { node(func: type(Account)) @recurse(depth:3){ uid expand(_all_) } } ``` return : ```auto "data": { "node": [ { "uid": "0x27", "Account.email": "test2test@test.com" } ] }, ``` And when I query Session : ```auto { node(func: type(Session)) @recurse(depth:3){ expand(_all_) } } ``` it returns : ```auto "data": { "node": [ { "Session.account": { "Account.email": "test2test@test.com" }, "Session.mail_to": "test2@test.fr", "Session.mail_from": "mf@rlol2.fr", "Session.mail_text": "text222" } ] } ``` So I have my account that is stored in Session but isn’t returned by Account’s sessions array… what am I doing wrong ? Thanks ---
**Author:** ![chewxy](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/chewxy/32/4339_2.png) [@chewxy](https://discuss.dgraph.io/u/chewxy)\ **Post date:** [April 5, 2021, 11:44pm UTC](https://discuss.dgraph.io/t/id-and-hasinverse-on-specific-type/13530/2 "2021-04-05T23:44:57Z")
Hi there @lzr , welcome to the Dgraph community! I noticed something strange about your schema: you have TWO `@hasInverse`s . Based on what you want to do, the following schema is more than enough: ```auto type Account { email: String! @id @search(by: [hash, regexp]) sessions: [Session] @hasInverse(field: account) } type Session { id: ID! account: Account! # THIS WAS REMOVED. mail_to: String! @search(by: [hash, regexp]) mail_from: String! @search(by: [hash, regexp]) mail_text: String! mail_html: String! mail_subject: String! @search(by: [hash, regexp]) mail_original: String! } ``` Now on to your questions: > [@lzr](#): > > In theory, if I insert an account, the email **is the only id** (when i’m querying dgraph, I always end up with **uid that are generated** … is that normal? It’s normal. > [@lzr](#): > > so in my case if I create several time an account with the SAME email I end up with several time the SAME email in dgraph … with the @id there sshould be only one no ?) That’s funny. That shouldn’t happen. I will try to reproduce based on your queries/code > [@lzr](#): > > If I create a session with an account linked to it, when I query that account, I’m suppose to get an array of session ? > in my case when I request account, I don’t get the array of sessions : I noticed you used `expand(_all_)`. That function only expands terminal nodes. To get the sessions, you need to do this: ```auto { node(func: type(Account)) @recurse(depth:3){ uid expand(_all_) Account.sessions {} } } ``` ---
**Author:** ![lzr](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/lzr/32/7493_2.png) [@lzr](https://discuss.dgraph.io/u/lzr)\ **Post date:** [April 12, 2021, 3:08pm UTC](https://discuss.dgraph.io/t/id-and-hasinverse-on-specific-type/13530/3 "2021-04-12T15:08:49Z")
Hello, thanks for your answer, when I use your request : > [@chewxy](#): > > ```auto > { > node(func: type(Account)) @recurse(depth:3){ > uid > expand(_all_) > Account.sessions {} > } > } > > ``` I get the following error : ```auto "message": ": Repeated subgraph: [Account.sessions] while using expand()", ```