How to update single data when using Fauna and GraphQL - graphql

I have some problems when using Fauna and GraphQL
When I use GraphQL to update data, all parameters are required
For example
// Schema
type User {
username: String!
password: String!
phone: String!
}
// Mutation
mutation {
updateUser(id: "xxxxx", {"phone": "+886 110220330"}){
username,
phone
}
}
// Error
But I only want to update the phone data this time, how can I skip other parameters?
Although it can solve the problem when I delete the Not null of all attributes in User type,
But it doesn't look like a good way and safe
// after
// Schema
type User {
username: String
password: String
phone: String
}

There is a preview feature that you can use by adding a header to your GraphQL query.
X-Schema-Preview: partial-update-mutation
Once you do this, you will have access to a new mutation called partialUpdateUser which will make all of the input values optional.
See the docs for more information: https://docs.fauna.com/fauna/current/api/graphql/previews/

Related

GraphQL variable combination validation

Imagine the following (simplified) GraphQL schema:
type User {
username: String
email: String
}
type Query {
user(username: String, email: String): User
}
If I would only want to allow querying user by giving a username, I would of course change it to user(username: String!), making the username required using the exclamation mark. Same thing vice versa with the email.
Is it possible though to have a GraphQL native solution where I validate for the existence of only either one (logical XOR) or at least one (logical OR) of the two input parameters?
Of course I could do it in the query resolver manually, but a #constraint directive like it is being used in Apollo GraphQL spreading across variables would be nice.
Directly ... not possible:
check fields existence [within args] on resolver;
use #constraint to check each field shape;
Indirectly:
you can try to use union of input types:
.
type UserNameInput {
username: String!
}
type UserEmailInput {
email: String!
}
type UserInput = UserNameInput | UserEmailInput
type Query {
user(input: UserInput): User
}

How to properly append to an array using Dgraph GraphQL API?

I'm trying to spin up Dgraph, but appears as though to add a node to an array of nodes using the GraphQL api requires an unnecessary amount of work if I understand it correctly:
I have the following simplified schema:
type User #secret(field: "password") {
account: String! #id
email: String! #search(by: [hash])
extension: String! #search(by: [hash])
phone: String! #search(by: [hash])
hasCreated: [Transaction]! #hasInverse(field: from)
hasReceived: [Transaction]! #hasInverse(field: to)
}
type Transaction {
id: ID!
type: TransactionType! #search(by:[terms])
amount: Float!
assetCode: String! #search(by:[terms])
to: User!
from: User!
initiatedAt: DateTime! #search(by:[hash])
completedAt: DateTime #search(by:[hash])
status: Status!
}
To me, it appears as though to add a node to the User's hasCreated or hasReceived fields would require me to pull the entire array, append a new Transaction to the array and then use an updateUser mutation to complete the update. But the updateUser mutation would require me to get all the Transactions and all Users attached to these transactions and so on.
Example trying to retrieve an entire user object:
query {
getUser(id:"%s"){
account
email
extension
phone
hasCreated {
id
type
amount
assetCode
to {
...
}
}
hasReceived {
id
type
amount
assetCode
to {
...
}
}
}
}
}
Is there another way to append to arrays or update objects using the GraphQL api without having to retrieve whole objects?

Graphql input mandatory property

Is there a possibility to create a GraphQL input with a mandatory input or another.
For example :
input ClientInput
{
name: String!
token: String!
email: String!
}
I want one of the properties token or email to be mandatory.
If one of these is provided, the other becomes optional.
Is it possible ?
If not, is there a kind of "workaround" ?
No, this is not possible. One workaround would be to make the two fields aptional, then do manual validation, upon which you can return custom errors.
Another way would be to combine the fields into something like
input ClientInput
{
name: String!
tokenOrEmail: String!
}
By doing this you can make the field mandatory, then do some parsing to determine whether the provided value is token or email
An even better way would be to add another field to provide the authMethod, like so:
input ClientInput
{
name: String!
authData: String!
authMethod: AuthMethod!
}
enum AuthMethod {
EMAIL
TOKEN
}

Overload GraphQL Schema to Support getting a user by username or password

I am trying to create a GraphQL Schema such that a user will be able to find a user by their email or username. Imagine for these purposes one user could have an email that is the username of another user.
My typeDefs look as follows:
const typeDefs = gql`
type Query {
user: User(username: String!)
user: User(email: String!)
}
`;
Is this a valid Schema? If not how would I change my solution to be valid and solve my problem?
Edit: So I tried to execute the above and I get an error: 'Error: Field "Query.user" can only be defined once.' As I thought I might.
Is there any way to ensure that exactly one of username and email is null in the following: user: User(username: String, email: String)?
There is no "overloading" of fields in GraphQL, and no syntax that would support one of two fields being required. An argument is either nullable or non-null, that's it. You can do this:
type Query {
user(username: String, email: String): User
}
or this
type Query {
user(filter: UserFilter!): User
}
input UserFilter {
username: String
email: String
}
and then handle validation (at least one argument is defined but not both) inside your resolver. The only other way to do it would be something like:
type Query {
user(key: UserFilterKey!, value: String!): User
}
enum UserFilterKey {
username
email
}
But this kind of approach is not very intuitive for anyone consuming the schema. It also only works if the arguments in question have the same type.

AWS-Amplify API module: how to make GraphQL fields unique?

AWS-Amplify provides a couple of directives to build an GraphQL-API. But I haven't found out how to ensure uniqueness for fields.
I want to do something like in GraphCool:
type Tag #model #searchable {
id: ID!
label: String! #isUnique
}
This is an AWS-Amplify specific question. It's not about how to do this with generic GraphQL. It's very specifically about how to do this with AWS-Amplify's API module. (https://aws-amplify.github.io/docs/js/api)
Hey thanks for the question. This is not yet possible by default using the amplify-cli but you could do this yourself using pipeline resolvers and an extra index on your DynamoDB table. The steps to do this are as follows:
Create a GSI on the table where the label is the HASH KEY.
Create a pipeline resolver on the Mutation.createTag field in your schema. You can turn off the auto-generated Mutation.createTag mutation by changing your #model definition to #model(mutations: { update: "updateTag", delete: "deleteTag" }).
Create a function named LookupLabel that issues a Query against the new GSI where the label = $ctx.args.input.label. If this returns a value, throw an error with $util.error("Label is not unique"). If it returns no values then continue.
Create a function named CreateTag that issues a PutItem against the Tag table.
Add those two functions in order to your pipeline resolver.
You can read more about pipeline resolvers here https://docs.aws.amazon.com/appsync/latest/devguide/pipeline-resolvers.html.
As of writing amplify does not yet support custom & pipeline resolvers but you can read more about the feature here https://github.com/aws-amplify/amplify-cli/issues/574 as it will be supported in the future. For now you can add the resolver manually in the AWS AppSync console or via your own CloudFormation template that targets the id of the API created by Amplify. It would also be helpful if you create an issue here (https://github.com/aws-amplify/amplify-cli/issues) and tag this as a feature request because it would be possible to automate this with an #unique directive but this would need to be planned.
Thanks
Update: now you can use #primarykey and #index annotations:
https://docs.amplify.aws/cli/migration/transformer-migration/#what-is-changing
basic:
profile #model {
name
email #primaryKey - has to be unique
other
}
so if you needed something like:
profile #model {
name
email: String! #hasOne
other
}
email #model {
email: String! #primaryKey
}
if you are on an older version see below
I will eventually be testing this out to see if this works but you might be able to do something like rename the id to a string!
so...
type Tag #model #key["id"] {
id: String!
}
or:
type Customer #model #key(fields: ["email"]) {
email: String!
username: String
}
this second one is taken directly from the docs: https://docs.amplify.aws/cli/graphql-transformer/key#designing-data-models-using-key
The docs were updated recently so hopefully they are easier for everyone to understand.
If you need a more advanced workflow with allot of keys, and stuff like that then you just have to separate things out and make more types for example:
type Customer #model {
id: String!
email: Email! #hasOne
username: String
}
type email #model #key(fields: ["email"]) {
email: String!
}

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