Int type parameter of custom dql is wrong

[asuka]

I defined the following custom dql query:

type Query {
    getTest(first: Int!): [User] @custom(dql: """ 
        query q($first: int!) {
            getTest(func: type(User),first: $first) {
                id: User.id
                name: User.name
            }
        }
    """)
}

When I execute the following query, it works:

query{
  getTest(first:  12){
    id
    name
  }
}

When I changed to variable execution, it threw an error:

query($first: Int!){
   getTest(first:  $first){
    id
    name
  }
}

The error:

"errors": [
    {
      "message": "couldn't convert argument first to string because provided value is not a scalar, can't convert it to string"
    }
]

The above is the result of my test in altair client.

If I change the type of first to first: String, the above error will no longer appear, but it does not meet my expectations. first should be of type int.

[MichelDiz]

@asuka

query($first: Int!){
   getTest(first:  $first){

PS, ignore this - This answer is wrong. Not a duplicated issue.

This is not supported, and it is duplicated of

Support value variables for paging params (offset, after, first)

Moved from GitHub dgraph/2564 Posted by disconsented: { var(func: eq(account, "100")){ client{ cid as uid } msg as message_limit } messageCount(func: uid(cid)){ count(messages) messages(orderdesc: timestamp, offset: val(msg)){ uid payload timestamp } } } message_limit here is message_limit:int . . The essential point is that I want to be able to set values in the database to use as limits application side. The above results in : st…

[asuka]

@MichelDiz Will it be implemented later?
I use http to call the GraphQL API. According to the GraphQL specification, I must write it like this.

@asuka

query($first: Int!){
   getTest(first:  $first){
    id
    name
  }
}

To make it work, I temporarily changed the type of first to String.

@asuka

query($first: String!){
   getTest(first:  $first){
    id
    name
  }
}

Hope to correct it later.

[MichelDiz]

@asuka

Will it be implemented later?

It is in the back-log and it is popular. So, 99,9999% yes.

@asuka

To make it work, I temporarily changed the type of first to String.

But this works in DQL?

[asuka]

@MichelDiz

But this works in DQL?

Yeah, It works.

type Query {
    getTest(first: String!): [User] @custom(dql: """ 
        query q($first: string!) {
            getTest(func: type(User),first: $first) {
                id: User.id
                name: User.name
            }
        }
    """)
}

It will work after changing to String type.
Looking forward to improving this feature soon.

[amaster507 (Anthony Master)]

@MichelDiz

But this works in DQL?

it works in GQL as is illustrated above and as categorized. Your referenced issue was DQL.

@michaelcompton is there a reason why the input of first works with String and not Int?

@asuka

couldn't convert argument first to string because provided value is not a scalar, can't convert it to string

This error seems like it stems from after the query gets rewritten to DQL. This does not seem like a normal type error from the graphQL logic.

[MichelDiz]

@amaster507

it works in GQL as is illustrated above and as categorized. Your referenced issue was DQL.

My confusion was about the type of variables. Just now I noticed that I confused DQL Vars with Value Vars. My reference above is about Value Vars, not DQL.

@amaster507

This error seems like it stems from after the query gets rewritten to DQL. This does not seem like a normal type error from the graphQL logic.

That feels like a GraphQL parsing error

See

Run

query q($first: int) {
  getTest(func: type(Film),first: $first) {
    uid
    expand(_all_)
  }
}

In Dgraph Ratel Dashboard

So, @asuka, sorry for my mistake. DQL Vars and Value Vars are totally different things. Not sure why this parsing error happens. As INT is supported by DQL Vars.

@abhimanyusinghgaur do you have any idea about it?

[abhimanyusinghgaur]

It is a bug with respect to variable handling in GraphQL. Numbers from variables are parsed as json.Number and not int or float scalar types. There is a missing case for json.Number during the conversion to DQL variables.
Will have a PR for it soon.

[abhimanyusinghgaur]

Here is the PR: fix(GraphQL): correct GraphQL variable propagation to custom-dql by abhimanyusinghgaur · Pull Request #6433 · dgraph-io/dgraph · GitHub
Hope to get it merged today.

[MichelDiz]

Nice! thanks The Flash!

BTW @asuka, you don’t need to add ! in DQL the exclamation has no effect. As fas as I remember.

[asuka]

@MichelDiz

@MichelDiz

in DQL the exclamation has no effect

Ok. But how to distinguish between required and optional?

[abhimanyusinghgaur]

@asuka

But how to distinguish between required and optional?

@MichelDiz meant that ! won’t have any effect in DQL. It is a feature only in GraphQL.

@asuka

getTest(first: Int!): [User] @custom(dql: """

So, in the above line, it will make the first argument as NON_NULL. But, you don’t need to apply it inside DQL as you have done it in the next line after the above line:

@asuka

query q($first: int!) {

So, to clarify your question, with GraphQL you can distinguish between required and optional but DQL has no such concept. So, just having the following query will make it a required argument:

type Query {
    getTest(first: Int!): [User] @custom(dql: """ 
        query q($first: int) {
            getTest(func: type(User),first: $first) {
                id: User.id
                name: User.name
            }
        }
    """)
}

[asuka]

@abhimanyusinghgaur Thanks, I see.