Using ID in GraphQL parametrized query - graphql

Question

I have the following schema:
type Post {
id: ID!
text: String
}
I am using autogenerated mutations from neo4j-graphql.js, so I have access to the following mutation:
UpdatePost(
id: ID!
text: String
): Post
The issue:
When I'm using the following query:
mutation update($id: String, $text: String) {
UpdatePost(id: $id, text: $text) {
id
text
}
}
With the following parameters:
{
"id": "a19289b3-a191-46e2-9912-5a3d1b067cb2",
"text": "text"
}
I get the following error:
{
"error": {
"errors": [
{
"message": "Variable \"$id\" of type \"String\" used in position expecting type \"ID!\".",
"locations": [
{
"line": 1,
"column": 17
},
{
"line": 2,
"column": 18
}
],
"extensions": {
"code": "GRAPHQL_VALIDATION_FAILED"
}
}
]
}
}
Is there a way to convert my string ID to the actual ID type? Or circumvent this error altogether?

Answer 1

The error you're seeing is related to the type of your variables as specified in your query's variable definitions. It has nothing to do with the values of the variables (which appear to be correct). Based on the error message, the type of your $id variable is String, not ID as shown in the query you pasted.
Regardless, because the type of the id argument (where the $id variable is being used) is ID!, not ID, then your variable's type should also be ID!.
The ! indicates a non-null (required) type. In other words, the id argument must always be provided and it cannot be given the value null. Any variable passed the argument must also be non-null. If the variable's type is ID instead of ID!, we're telling GraphQL the variable might be omitted or have a null value, which would be incompatible with the argument where it's being used.
Note that the opposite is not true: if the argument's type was ID, then either an ID or ID! variable would be valid.

Answer 2

For anyone else encountering this issue, in the mutation definition you have:
mutation update($id: String, $text: String) {
UpdatePost(id: $id, text: $text) {
id
text
}
}
where you're explicitly saying the $id is a String, you need to change it to ID like so:
mutation update($id: ID, $text: String) {
UpdatePost(id: $id, text: $text) {
id
text
}
}
This is why you're seeing the error, because your query to update it's saying explicitly that ID is a type String hence the error.

Answer 3

In case someone else is looking for an answer, here's few example how to use ID variable in C#:
var request = new GraphQLRequest
{
Query = #"
query getToken($tokenId: ID!){{
tokens(where: {{ id: $tokenId}} orderBy: decimals, orderDirection: desc) {{
id
symbol
name
}}
}}", Variables = new
{
tokenId = "<stringValue>"
}
};
And for using lists:
query getToken($tokenIds: [ID!]){{
tokens(where: {{ id_in: $tokenIds}} orderBy: decimals, orderDirection: desc) {{
id
symbol
name
}}
}}", Variables = new
{
tokenIds = new ArrayList(<yourStringArrayListValue>)
}